Chevy 3.1 Liter Engine: Leaking Intake Manifold Gasket and Warped Heads

Upper intake manifold, Chevy 3.1-liter engine
Upper intake manifold, Chevy 3.1-liter engine

The Chevy 3.1-liter engine has a notorious weakness, a failure mode that GM will not cover after the warranty expires. The lower intake manifold gasket fails and leaks coolant into the engine oil.

I had the dealership replace the manifold gasket the first time at about 40,000 miles, before it got to the point of leaking coolant into the oil. This cost me $1200, mostly for labor. Then, just 15,000 miles later, the gasket failed again. This time coolant leaked into the oil; the give-away was the milky substance that could be seen on the oil filler cap.

Realizing I was looking at another repair bill over fifteen hundred dollars, I decided to do the job myself and do it right. The first time, I didn't do the job myself because I didn’t have the time; also, I was a little intimidated by the fuel injection system, two intake manifolds, the special tools I would need to complete the repair, and the manual’s complicated procedures for removing all the different parts of the upper engine. The time element was a reasonable excuse, but the intimidation element was not. If you can change your own oil, replace belts, and change spark plugs and filters—which is a basic tune-up—then you can do this job.

How to Prepare for an Intimidating Repair Job

This article will not take you step by step through the process of completing the repairs; you will need a manual for that. But this article will help you avoid some common mistakes everyone makes when they work on their car. We learn from our mistakes, and believe me I have learned a lot. A little more preparation in the beginning will save you a major headache later.

Before you begin the tear-down, you will need to do some preliminary research. First, go to the auto parts store and buy the repair manual for your make and model car. Next, pick up a few car magazines. They usually have articles on replacing intake manifold gaskets and rebuilding cylinder heads. The articles are easier to read than the manual. You can find even more articles archived on the websites for these magazines. Once you have read as many articles as you can find, you will realize that pulling the heads off of any car is a rather straightforward process.

Now you need to see if you have all the tools you need to do the job. A basic toolbox with socket wrenches, box wrenches, flare wrenches, and screwdrivers should cover most of your needs. Just make sure they are metric, since most cars today have metric nuts and bolts. You will need some specialty tools; however, most auto parts stores have a rent-a-tool program, sometimes at nominal cost and sometimes for free. For some tools there is a hefty deposit, but it is credited back to you when you bring the tool back.

I would suggest that you consider buying a breaker bar; it is a must to break (loosen) the head bolts. A torque wrench is also worth the expense; the click type is better than the bar and scale. The torque requirements of the head bolts and the lower intake manifold bolts are specified in the manual, and should be followed, since the head is aluminum and thus a little vulnerable to damage. If you over-torque the bolt you can cause the bolts to break; if you under-torque the bolt it may cause the gasket to leak and you'll need another repair.

Get your digital camera out and start snapping pictures of the engine. Take pictures of every wire connection you can see. Don't say, "Oh that’s so obvious, I don’t need to take a picture of that." Trust me, it will save you hours of frustration later. Next, get a roll of blue painter's tape and a red sharpie; this will allow you to label every connection. I suggest red because the tape will get dirty and make the label hard to read. I label connections as "A to A," "B to B," "C to C," and so on. Take a picture of every part before you remove it, then take a picture of whatever the part came off of. The more reference points you have the better.

Zip-lock bags are a must. Put all the nuts, bolts, small gaskets, and small parts you remove into a bag; then label the bag with the name of the particular part. Seal the bag and put it in a safe, clean area where it will not get lost or moved. Following this practice, you won't waste time looking for a part later on when you are putting the pieces back together.

You will need some miscellaneous items, all of which you can get at an auto parts store:

  • container for the coolant
  • container for the oil
  • a floor jack
  • two jack stands
  • mechanic's magnetic pick-up tool
  • socket extensions
  • socket adapters (1/4 inch and 1/2 inch)
  • a magnetic fluorescent drop light

Set up a workbench (two saw horses and a couple of boards will do the trick) and pick up some kitty litter.

Once you have gathered all the necessary tools, you are now ready to begin the job of fixing your own car. Follow the manual carefully. If you're not sure about a procedure, take a break and re-read the procedure again. After the second or third read, the procedure will make sense.

It looks complicated.  Go slowly and keep checking your manual.
It looks complicated. Go slowly and keep checking your manual.

Dissassembling the Chevy 3.1-Liter Engine

The basic steps in the tear-down are not difficult. With the engine completely cooled, disconnect the negative battery cable, drain the oil out of the block into the oil container, and drain the coolant into the coolant container. Make sure you drain enough of the coolant out of the engine so that when you take the heads off, the coolant will not spill over into the open cylinders. (Here is where the kitty litter comes in handy; spread it over any spills you make, let it absorb all the fluid, then sweep it up and the spill is gone.) Spray all bolts that look rusted with WD-40. I'd do this the night before; it will penetrate the rust and make loosening the bolts easier.

With the car drained of fluids, you are now ready to begin removing parts. Remember to take pictures and follow the manual’s procedures. The order in which you will take off parts will depend on your make and model. As an example, the video below shows the disassembly sequence on an ‘04 Buick Century. On my '02 Chevy Malibu, the sequence begins:

  • Disconnect the air cleaner.
  • Take off the plenum.
  • Disconnect the PCV valve and push it out of the way.
  • Disconnect the heater bypass hoses and clamp them off (or jam sharpie pens into the hoses, this works just as good as a clamp).
  • Disconnect the thermostat by-pass pipe and remove it. Be careful with the quick-disconnects on those hoses, they break easily. (The good news is a replacement quick-disconnect is inexpensive, maybe five dollars at the most).
  • Last, disconnect the thermostat housing.

Accessing the Lower Intake Manifold Gasket on a 2004 Buick Century

Removing the Ignition Coil Pack

Removing the ignition coil pack is going to be your first area of self-doubt, but don’t worry. Keep on working and start disconnecting the spark plug wires from the spark plugs. Label each wire with the cylinder number it came off of. If you do one at a time and label each wire, you will not have a problem. Leave the wires connected to the coil pack. The coil pack is connected to a plate which fits over two posts, coming out of the head, and is bolted down with two nuts. Remove the nuts and lift the pack off the posts. You'll see the electrical connection that goes to the fuel rail; label it and disconnect it.

ignition coil pack
ignition coil pack

Removing Upper Intake Manifold and Valve Covers

You are now ready to remove the upper intake manifold. Depending on the make and model of your car you'll have to remove either six bolts or eight bolts. After you remove each one, bag it and label it.

The next step is to remove the valve covers, four bolts to each cover. The only one that will give you any trouble is the bottom bolt of the rear cover on the driver’s side. Due to the post for the ignition coil pack, you cannot use a regular socket wrench. You’ll have to buy a ratchet box wrench—I think I needed an 8 mm wrench. Otherwise you’ll be fighting the bolt and rounding its edges. If that happens, you’ll never get the bolt out.

Valve covers after removal.  The yellowish creamy gunk means coolant has gotten into the oil.
Valve covers after removal. The yellowish creamy gunk means coolant has gotten into the oil.

Removing Exhaust Manifolds, Fuel Rail, and Alternator

I decided to take the exhaust manifolds off next because I was a little intimidated by the fuel rail and wanted to leave it for the next day. The exhaust manifolds are not difficult to remove; just follow the directions in the manual and you will have them off in no time.

The fuel rail is actually very easy to remove. Just relieve the fuel pressure in the line (with the pressure relief gauge you rented), disconnect the inlet line and the regulator line, and pull up on the rail; all six fuel injectors will pop out. Replace all the O-rings when you reassemble the fuel rail.

You will have to remove the alternator. The manual is very straightforward on removal and installation. The tensioner pulley is released by using a ¼ inch ratchet (no socket attached) with a short length of pipe on the end to give you enough leverage to release the tension. Don’t try to release the tension without a short handled extension on the ratchet. You will not have enough leverage.

Removing the Lower Intake Manifold

The lower intake manifold is the tricky part. You have to jack up the motor and remove the passenger-side motor mount in order to remove one of the bolts from the intake manifold. The power steering reservoir is bolted to the block right over one of the bolts to the lower intake manifold. To take the reservoir off you need to remove the motor mount.

First, loosen the motor mount bolts with the breaker bar just enough so they'll be easy to turn when the engine is jacked up. Get the floor jack and a short piece of hard wood. Place the wood across the bottom of the oil pan towards the edge of the passenger side. Slowly jack the engine to take the weight off the mount. You can now remove the mount completely. Once the mount is removed, you will have access to the power steering reservoir attaching bolts. Follow the manual’s direction to remove the bolts and move the reservoir out of the way. DO NOT disconnect any hoses. Re-attach the motor mount and remove the jack.

You now have access to all the lower intake manifold bolts; just follow the directions in the manual. Remove the bolts in the numbered order given in the manual. Take a piece of cardboard (for example a cardboard box used to ship copy paper), and each time you take out a bolt, punch a hole in the cardboard, push the bolt into the hole, and label the hole with its number in the sequence. Once all the bolts are removed, the lower intake manifold is ready to be taken off and set aside.

The source of the problem:  bad intake gaskets
The source of the problem: bad intake gaskets

Removing Cylinder Heads

One of the problems with aluminum heads is that they warp very easily. If you have gotten this far, you might as well remove the heads and send them out to a shop for reconditioning. At the time of this writing, it cost me $140 to have the heads checked, cleaned and milled. Since they were in fact warped, it was worth the money.

The cylinder heads are not difficult to remove at all. First remove the valve springs so you can pull out the push rods. Next, loosen the bolts, in sequence, a quarter of a turn, until you can turn then by hand. Remove the bolts and place them in the cardboard holder. Make sure you number the bolts in the right sequence. You will need to remove the lifter retaining guides. Each one is held in place by two screws. DO NOT forget to put them back in, or you are going to have major problems.

The heads are ready to be removed. A word of caution here: these aluminum heads have locator pins that can be lost very easily, so be careful when taking the heads off. There are two on the rear edge of each head. These pins help to properly place the head gasket, so don’t lose them.

Preparing for Reassembly

You have completed the tear-down. Now send the heads to the shop to be reconditioned. While they’re at the shop, go to the auto parts store and pick up a gasket kit for a valve job, cheap oil and filter, one gallon of anti-freeze, a can of gasket remover, one tube of Black RTV silicon gasket maker, one tube of Red RTV, and a new thermostat. While you are waiting for the heads to come back from the shop, clean off all the mating surfaces with gasket cleaner, being careful not to gouge any of the surfaces. Clean up the valve covers and the two intake manifolds with Easy-Off Oven Cleaner. Spray it on the surface of the part, set the part in the sun for a few hours, and then wash the part off. The Easy-Off dissolves the grease and oil.

Here are a few things the manual does not tell you.

  • Make sure you use quality gaskets. This whole hassle is caused by the cheap gasket GM used when they originally put this engine together.
  • Your push rods are two different lengths: the short push rods are for the intake valves and the long push rods are for the exhaust valves. If you mix these up, your heads will be destroyed.
  • While you’re waiting for the heads to come back from the shop, cover the opening to the engine with shop rags or a plastic garbage bag. Any debris—leaves, dirt, acorns, pine needles—that gets into the engine will reduce the life of your engine considerably.
  • Remember to reinstall the lifter guide plates before you reinstall the lower intake manifold.

The heads.  Don't forget to reinstall the plastic lifter guides. The coil pack installation post can be seen on the head to the right.
The heads. Don't forget to reinstall the plastic lifter guides. The coil pack installation post can be seen on the head to the right.

Reassembly of the Chevy 3.1-L Engine

Putting the pieces back together should not be a problem, since you took it apart and took pictures. just take your time and be patient. Follow the manual carefully. Reinstall the parts in the reverse order that you took them out. The black RTV is used on the front and rear mating surface of the engine block; also, put a little bead of black RTV around the water jacket openings. The red RTV is used on the thermostat gasket. Once everything is bolted back on and the electrical connections are made, refill the engine with fluids. You might want to use the same coolant you drained from the engine; just top it off if you need to from the gallon bottle you bought. Start the car and check for leaks.

If everything checks out, take the car to a quick-lube shop and have them replace the cheap oil and filter with a good grade of oil and a good filter. Also, have the shop drain and replace the old coolant. I recommend paying someone else to change the oil and coolant because of the disposal issue. Trying to get a place to dispose of contaminated oil and coolant is difficult. Save yourself the hassle and have the quick lube place do it for you. They might even take the original contaminated oil off your hands, ask them—all they can do is say no.

When this project is completed, you will have successfully rebuilt the top end of your engine yourself, and you will know the job was done right because you did it. Try to fix it yourself first before you call in a professional. The worst you can do is break it some more, and if you succeed, you will save a lot of money.

A word of caution: This article is meant as a reference only. Follow not all the safety procedures as well as the repair procedures. For example, never get under a car without using a jack stand, and never open the radiator cap of a hot engine.

Comments 161 comments

William Green 3 years ago from USA Author

DCook, your friend is right. Whether it is a cracked piston or worn rings. IT is a difficult job for the DIYer. The reason being. IF you pull the piston and change it or re-ing it you need to change the bearings on the rod cap lower and upper. The lower cap is easy just take out the old one and replace with the new one. The upper cap bearing has to be rolled out because you have the crankshaft blocking direct access. I have never done this procedure before, but I have read about it. IT seems straight forward; however working on cars is never straight forward when it is your first time doing a new procedure. What you need to consider:

1. read everything you can on re-ring or re-placing a piston.

2. If you do one piston do you need to do all the pistons.

3. Do you want to pull the engine or leave it in to do the job

4. Est the time to do the job then double it.

5. cost vs time off the road is this your primary car or a project car.

Good luck


DCooke 3 years ago

William, thanks for the information. I did find a broken lifter in the very far left corner facing the firewall. A fellow that has rebuilt a number of chevy 3.1 L engines said the camshaft may have to be replaced or even a piston may be broken. He said to take out spark plug out at that corner and pump air into ito it at around 80 psi. If normal hissing is heard then piston is okay but if big whooshing sound then ring and/or piston is probably shot. Any ideas?

William Green 3 years ago from USA Author

John you need to buy a torq wrench in inches not foot pound. hope this helps

William Green 3 years ago from USA Author

DCook at 150k miles I would take the heads off and have them done replace all the gasket.

John4 3 years ago

I just did the head gasket job on my lumina

How do you adjust the lifters

The book says to torque to 14# but I don't have a torque wrench that goes that low

Thanks for the thread it was very helpful

DCooke 3 years ago

I am about ready to take apart my 3.1 engine on a 1993 Lumina auto. I know it is seriously leaking oil. Will the heads have to be removed since it has a little over 150,000 miles on the engine.? What other parts could be leaking oil besides intake and exhaust gaskets, upper manifold gaskets, and valve cover gaskets?

William Green 4 years ago from USA Author

Hi Paul, I did not place grease under the module. I do not remember if the manual said to or not. If the manual calls for grease than I would do it.

Paul 4 years ago

Hey William, I too have the 3.1 litre in 2000 Malibu. Question: Did you place grease under the ignition module when you removed/re-installed? My Malibu manual says to do it for the 2.4 litre engine, but says nothing about whether to do it for 3.1 litre.

Thank you in advance.

darrell 4 years ago

just had this happen to me today, feeling kinda scared to do this, i am very mechanical but kinda intimidated to do the job, going to find a manual for 95 lumina

Jay Sanderson profile image

Jay Sanderson 4 years ago

Update on my project,

job went without any big issues, did it on a very casual basis over a few days (longer wait time for head bolts to arrive) spent about 3-4 hrs over 3 days in 95°f garage. heads were surfaced and checked, they were not warped much but worth the extra time and $ (only $50 for re-surface) engine was loud at first start up and had a "bad bearing" type growl sound and lifter noise, it all cleared up after worm up and has not showed up again, the noise may have been a heat shield vibrating?? the engine now runs smooth and strong, I never drove this car before repair, it's a little hot rod in a light weight 2 door Grand Am!

Please note, my research showed that torque specs in most manuals are incorect IF you are using newer/updated gaskets.

* if you use old (lower torque) values with newer type lower intake gaskets that have metal crush sleeves you run the risk of same intake leak,

*also on head bolts, there is a higher torque value that dealers and updated technicians use when doing this job (with new bolts)

William Green 4 years ago from USA Author

I'm not familiar with the 94 3.1 but it sounds like the intake gasket is leaking coolant into the oil. If that is the case you will have to replace the gaskets. To put your mind at ease you can take the car to a shop and have them check it out. You will pay for the estimate but at least your concerns will be eased.

good luck.

denlp 4 years ago

have 1994 cutlass supreme convertible with 3.1, low coolant lite on today. about a gal low, checked oil dipstick and oil very runny, checked filler cap and milky. What should I do? Help!!

William Green 4 years ago from USA Author

Jay, If you still have the original head bolts, look at the markings on the top and compare them to the chart in the repair manual. That should give you the torq amount. If the number is somewhere in between 37 and 44 I would use it. It is up to you. good luck

Jay Sanderson profile image

Jay Sanderson 4 years ago


it's more the torque amount I'm worried about, 44 or 37 lbs tq.

William Green 4 years ago from USA Author

Jay, I don't know the revised seq for the 1998 3.1; but when in doubt, start in the middle and criss cross your seq outward. If possible do not use the old head bolts. Wait for the new bolts if you can.

Thanks again for the support.

Jay Sanderson profile image

Jay Sanderson 4 years ago

For the miles most these cars have and not always knowing how hot they got, the heads just make sense to do (if you can). But for a shop trying to sell the additional shop hours ...could be tough no matter the circumstances.

on, "...huge potentential of a major engine failure if not re-assembelled proper. I've seen the after math, not good"

the biggest possible DIY problem is keeping push rods in correct place, that needs to be done, heads pulled or not, sure there is more work and potential for problems but if you are capable of getting this far??


do you (or anyone) know if the revised head torque specs apply to 1998 3.1L?

above online revised value is 44 ft lb tq + 95° and a little different sequence patern compared to service manual at 37 ft lb tq + 90°

-I would think this is due to better gaskets designs of today & maybe different design head bolts?? but that's not stated. I'm waiting on new bolts coming from local parts store but if they don't get here soon I may just use old ones, I'm leaning towards 37 ft lbs tq + 90° if I have to use old bolts.


William, more people like you taking time sharing & encouraging is what we need.


William Green 4 years ago from USA Author

Jay, thanks for the positive feedback.

My typo's bother me than the negative comments.

Jay Sanderson profile image

Jay Sanderson 4 years ago

remember, there are many more honest techs out there then ones overselling. recommending to do the heads is just good sense for helping someone or (if you run a business) to avoid comebacks, we make the decision based on source. If its a shop you you don't trust, get another opinion

William Green 4 years ago from USA Author

Wayne, When I had teeh Techs do the job it failed after 6 month. When I did teeh job I sent the heads out to be mag flux and guess what they were warpped. Aluminum heads have a nasty habit of warpping with very little over heating. I

Wayne 4 years ago

I have been a tech for over 20 years, doing head gaskets for a intake leak is over kill. I've done a lot of these and never had a problem. This is a OVER SELL and there is huge potentential of a major engine failure if not re-assembelled proper. (I've seen the after math, not good)

Jay Sanderson profile image

Jay Sanderson 4 years ago

Thanks for reply! I just ordered the full head gasket kit from Amazon, found local shop to resurface heads for $50 for pair, sounds low?? maybe they will get me with some disassembly charge. the compression test was185-195 psi in all cylinders

William Green 4 years ago from USA Author


IF you have been running the car for any length of time than your heads are warped. which means replacing the gaskeyt will not solve the problem. The milky oil means the gaskets are leaking into the oil and out of mating surfaces of the heads and the block.

If you are planning on selling it just take it to a dealership as a trade. Don't waste the money during the job halfway. It will start leaking shortly after you finish the job.

Jay Sanderson profile image

Jay Sanderson 4 years ago

Great write up & feed back, I have a 96 Grand Am with a (written in paint pen on intake) 98 Olds Achiva 3.1L, it looks all the same as yours and others. it has the milk shake oil and low coolant, she said it was not over heated and stopped using as soon as oil slop was seen, Question, water was added over a few days and I assume the crankcase is way over full with the oil/water mix, but there was a good size puddle of oil under car, I can't tell from where yet. is this blow by from overfill or is it likely something something else is up?

I'm doing compression check tomorrow. if it checks out Okay (what should I expect?) I plan on just doing the the intake and sell it after, if I was going to keep, I would do the heads completely with new bolts. the part # for just the intake kit upper & lower from Felpro is #ms90562 (its supposed to have spacers at bolt holes to prevent deformation compared to previous designs) available on Amazon or oreilys for about $50. ....the complete head gasket kit is felpro #hs9957pt2 for about $160. is this a wise move? I can hardly afford anything on this car but i need to at least get it running now. Thanks in Advance!

Jim 4 years ago

I tried to remove the valve springs to get the pushrods out just like you said.... That dont work so I went back to the way we did things 35 years ago and removed the ROCKER ARMS so I could get the pushrods out...Then I tanked them clean, changed the stem seals,( maybe this is where the valve springs have to be removed ) checked for straightness and wah-lah back together. Still a piece of crap engine and most of the cars left with it are not worth the price of gaskets and bolt kits

William Green 4 years ago from USA Author

Hi DarkFlame,

If I can help I will. What do you need?

DarkFlame 4 years ago

Hi are you still helping people out?

William Green 4 years ago from USA Author

Rooster I do apologize for missing your comment. The new coolant looks a lot like transmission fluid. It could be a gasket problem. Before you go tearing the engine apart I would strongly urge you to get it check by the dealer. Paying a diagnostic fee will be the best money you will spend. It could be a simple fix. You will still save money when you do the repairs yourself. Goodluck.

rooster29 4 years ago

i have a 2003 chevy malibu and clear oil and oil cap, but i am adding coolant to it about once every 1000 miles and i do have some what appears to be transmisson fluid in my reservior and have that white substance on the cap of it time to this transmission cooler issue or one of my gaskets?

William Green 4 years ago from USA Author

Brian, the water jets (ports) are on the end of each head. (2 per head) just use the RTV on that section of the gasket. You do not need a lot just smear a little RTV on the small rubber portion of the lower Intake gasket which meets with the water ports.

I'm not farmiliar with the gasket sets you mention so I'm afraid that I can't help you with that. However, if some post a comment concerning those gaskets I will get it up on line quickly.

BrianRamey 4 years ago

So far this thread has helped me as much as the Hayne's Manual. I used hyour shopping list and got the felpro performance gasket set from Advance Auto. The whole set, HST9957-PT2 lists for $235, but by buying the intake set and other gaskets individually, I was able to get everything on the list for about $165. I used code CCABIN, which is $10 off of $30, $20 off of $50, and $40 off of one hundred. I made two 100 dollar orders and a 30 dollar order and saved $90. Yay!

Question: The lower intake gasket set (MS 98004 T, with permadry plus gaskets) comes with instructions to use the black RTV on the front and rear. I'm assuming that's the flat part against the block that doesn't have a gasket. The instructions said the sealer cannot be used on the "side rails". What is that? You said put RTV around the water jets. You didn't mention the air intake ports? What is the side rail? The lower intake gaskets look like black rubber on a metal frame.

William Green 4 years ago from USA Author


On my engine the short push rods are for the intake valves and the long push rods are for the exhaust valves.

Did you keep them in order when you took them out?

Steve 4 years ago

Im changing intake manifold gasket and need to know which pushrod bolt goes to the exhaust long or short on a 3.1liter

BrianRamey 4 years ago

Wow, 2 years and you are still helping out. Perhaps you could help me?

My wife drives a 1995 Buick Regal with a 2 year old used engine. Last year she had a head gasket leak, and her ex husband changed out both head gaskets (I wasn't available, and he went to mechanic school). We've had missing coolant and skipping getting worse recently. A code scan showed cylinder 2 missing. Today I pulled all the spark plugs, pressurized the radiator for 2 hours at 16psi, blocked the plug holes with paper towels and turned over the engine. Water came out of cylinders 1 and 2 onto the paper towels. So I am assuming both head gaskets are leaking? Could it be the lower intake manifold?

I'm planning on pulling both heads tomorrow and taking them to the shop. Since it seems both gaskets failed, I'm planning on buying new bolts, chasing the threads in the bolt holes, and trying to clean them out with brake cleaner and compressed air from keyboard cleaner.

I saw you used Felpro gaskets. Advance has a set for 140-160 depending on valve seals, and a 'performance' set for a whopping $250. Will the regular gaskets work? Also, what about the copper permatex sealant? Would you use that on the head gaskets? If so, spray or tube?

Also, I notice a lot of people asking about missing coolant. Don't forget the 2 bleed valves for the radiator (top of thermostat driver's side and heater hose junction on passenger side).

Thank you for writing this article. I didn't know if the steering pump was going to have to come off or not. I already have the alternator and coils off.

William Green 4 years ago from USA Author

malibu, those are signs of a major gasket leak. You need to replace the lower intake gasket You should also take off the heads and send them out to be resurfaced.

good luck

malibu 4 years ago

Quick Question. I have the water/oil goop in the valve covers, but not on the dipstick. I hear a tapping (which everyone considers normal) on startup. Is there any recommendation you can give me to reduce the ticking? Also. What is the best way to do an "engine flush" to clean out the junk oil?

William Green 4 years ago from USA Author

CJ, did you send the heads out to be resurfaced? The heads might have been wrapped so when you put them back on it would not matter how tight you did the bolts. Did you replace all the head bolts and lower manifold bolts? this can also cause a problem.

CJ 4 years ago

Well we just did my intake gasket on my 99 grand am gt 3.4 and all was fine until about a week later it started idleing rough and got a random p0300 and then it switched to a p0302 code. Ive got coolant in spark plug 2 and its causeing missfires when running. I stopped using the car as of the moment but im trying to figure out what it could be. We made sure it was torqued correctly and rtv'd everything we had to.I am trying to find ways to figure out what the problem so i dont have to have a wasted gasket set on my hands when i pull it apart again.

William Green 4 years ago from USA Author

That is great Annie.

Maybe the gas cap is not screwed on tight. Same thing happened to me. tighten it down until the click then erase the trouble code.

William Green 4 years ago from USA Author

Andy, the manual, for a 1998 and later (3.1 liter), give the tighten sequences as a two step process.

Step 1 tighten to 168 inch -lbs

step two tighten an additional 30 degrees. DON'T tighten to 168 Foot lbs.

William Green 4 years ago from USA Author

Ryan, If the fluid is coming out the rear cylinder bank than it is a gasket problem.

annie 4 years ago

it's leak free now, thankfully! i just have one more question... my service engine light came on recently. i got it scanned at auto zone, said new fuel cap. bought that, light is still on. what could this be?

ANDY 4 years ago

is there a specific ft lb for the push rods?

Ryan 4 years ago

I have the 3.1 in my 98 monte ls. I parked it one day and it leaked a whole bunch of coolant on my driveway. I've been watching it for a few days, and it does not leak while running, but when I shut it off, it leaks a decent amount.

Today, I parked it in my flat garage, shut it off, and shook it back and forth, side to side, and up and down, and I had 4 decent drip spots on the floor of my garage. I took a flashlight and looked down the rear driver's side of the engine, right below the head, and behind the throttle body. It looks like there is fluid running down the back of the engine. What is this? Can you help me? Is this the gasket, or the manifold?

annie 4 years ago

I filled the line up to cold and within 2-3 days now the whole res will be empty... but there is no leak on the ground anywhere in sight, and if you run it for 20 or so minutes and watch it you still will see nothing leaking. It's not leaking into my oil pan (yay!) so the guy who's been doing work on it said it might be the thermostat?? He only had a few minutes to look at it today as I had to go to work, however, so he hasn't done a full inspection of it. It's just weird because there is no coolant in sight anywhere under the hood and it's not coming out under the car and it's not going into the oil. I'm just wondering where the heck it's disappearing to, it's like it's evaporating.

Thank you so much for your help so far!

William Green 4 years ago from USA Author

Annie are you sure you put enough coolant in the system. Before you do anything else double check the fluid level. Fill the res up to the line for cold. Run the engine if the res is empty try it one more time. If the res has fluid than you should be ok. If it is empty then you have another leak most likely the radiator. Good luck

annie 4 years ago

Hi. I got the water pump replaced, but the reservoir just went empty again so apparently it is still leaking from somewhere. :( It doesn't look wet inside at all (which it did before gasket/water pump replacement) so I'm wondering if maybe this time it's the radiator?? Ugh! Cars!

William Green 4 years ago from USA Author

Just Kris,

Good mechanics at reasonable rates are getting harder and harder to find. I am glad you have one stick with him.

Just Kris 4 years ago

I have a '98 Chevy Lumina and was dealing with overheating. That the radiator cap replaced and the thermostat. Had the air bled out and it ran fine for a couple of days. Overheated again and had the intake manifold replaced. Ran fine again for a few months and started overheating again. This time it was the water pump. No issues for about 6 months and then the car just shut off while I was driving. Fuel pump was just replaced. Thankfully I have a mechanic who guarantees his diagnosis and charges me a fraction of taking it to a dealer.

William Green 4 years ago from USA Author

Your friend is right it is the water pump

annie 4 years ago

Also might I add I have a 1996 Chevy Lumina, 3.1V6 :)

annie 4 years ago

I just had by upper & intake manifold gaskets replaced by a trusted friend who's been working on cars for years. The car runs much better, but is still leaking a whole reservoir of coolant a day. He says it's the water pump; backing it up is that the coolant puddle under the car is always only on the side of the water pump. Also, the engine only looks wet around where the water pump is instead of being completely soaked before the gasket replacement.

Would a failing water pump still cause such a bad leak, however (I assume it's been failing for a while, I've been fighting coolant problems on this car for years). I'm terrified that it might be my radiator.

johnnie 4 years ago

I have a 97' lumina (3100), and have been running into some overheating problems(mind you it's winter). A friend replaced the thermastat and bled the air out of the system, but still runs through coolant every 2 days and still overheats. I been reading alittle on the net about blown head gaskets and a few other things(including "steel seal") and still not sure what I should do yet. The car starts to overheat within the first 2 miles, engine hot light goes on for about 1-2 miles, then starts cooling itself again like its fine. Before I do anything, I would like to hear your input on the subject. I would greatly appreciate it. ty

Dave 4 years ago

I have a 1996 lumina and need help diagnosing. It died and won't stay running just backfires thru the intake. It's getting spArk and fuel.

William Green 4 years ago from USA Author


Sorry it took so long to get back to you, Work and life have kept me busy. It would not surprise me about the gauge flaw. However, I have never had that problem. Changing a sensor is pretty striaght forward just find it and unscrew it. Wrap the threads of the new gauge with teflon tape and put it in. Connect the wire connection and you should be all set. The only problem I foresee is loss of oil depending were the gauge is located. Sorry I can be of more help. Good luck

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thump1st 4 years ago

here's a question. How do I Replace the oil pressure sensor? My gauge is fully open a long with my fuel gauge & from what I've read if the oil pressure sensor has shorted out it'll affect the fuel gauge (gm design flaw).

William Green 4 years ago from USA Author

Dan, The knock could be from damaged main bearings, piston rod bearings, cam bearings, or lifters. What does the knock sound like. Is it a deep pitch or a high pitch knock? A deep pitch knock mostly likely means main bearings. A higher pitch knock could be cam bearings or lifters. No matter where the knock is coming from it sounds like bad bearings. If this is not fixed you will have an engine failure. You said your niece ran the engine without any oil in the pan. That will cause the bearings burn. You need to check all the bearings. That means a complete tear down. You will have to decided which is cheaper buying a used engine or fixing the one in the car. Good Luck

thump1st profile image

thump1st 4 years ago

I'm officially signed in (I'm Damien aka), thump1st. I went 2autozone, got that assorted o ring set. Put it on the end of that fuel rail. runs lovely now! Just need 2power clean that motor. Thank you William

William Green 4 years ago from USA Author

Damien, The same thing happened to me. You either forgot the o ring orthe o ring is bad. It is an easy fix. Good luck

Damien 4 years ago

I put everything back 2gether. When I turn the key 2start her up the fuel pump activates and fuel comes spewing out the fuel rail @ the connector line. Is there a gasket that I missed that was supposed 2go on the end of the hose? Or bad o ring(s)?

William Green 4 years ago from USA Author

Chevy 02 malibu. If this is your first time, you should plan on a day or two to do the job. Take your time do not rush. Good luck

Ruben D. 4 years ago

what car was your set up on.. i just kinda skimmed. i'm about to tackle a 3.1 on a 01' lumina (sedan). man i hope it as easy as this makes it out to be i can probably knock it out in a few hours. but i forgot about the draining fluids bit. damn, i have to wait till next week.

Andras 4 years ago

Thank you for the useful writeup, very informative!

I bought my '95 Chevy Lumina sedan 3.1l from an old lady, who was the original owner of the vehicle. I don't know if the intake manifold gasket was replaced or not, what is the mileage that they usually fail? I have 110k miles on it. Also, do valve stem seals known to fail at this mileage? My car uses about a qt of oil every 500 miles, no smoke though, only the smell. I did a compression test and read out between 180-200 psi. The spark plugs get this white powdery build-up- what led me to believe that my valve seals are leaking. I check and clean them about every 2000 miles. Any info is greatly appreciated!

William Green 5 years ago from USA Author

It could be a cracked head. Did you have the heads checked before you put them back on the block. Aluminum heads can crack due to slight overheating compared to cast iron heads.

Eric 5 years ago

Great Hub!. I did this job myself on a 3.4L, same steps. Got a problem now after 2 days of driving. It is overheating and smoking antifreeze. There were no leaks detected after the repair,and the coolant level has not dropped. What am I missing? I'm afraid it may be the block....Any thoughts?

drew 5 years ago

I have a 97 skylark 3.1

genadian 5 years ago from USA

I just did this on a 2002 Grand Prix. It started out with just A fuel injecter. I decided I would replace all of them. When I tried to remove the injecters from the lower intake the plastic tips popped off and went down into the lower intake. I pulled the lower intake to get the pieces out. I saw that the rods had to be pulled to replace the gaskets. I cleaned everything up and installed new gaskets. The only problem I found is after putting it all back together is the upper intake is leaking and is probably warped. I will replace it soon. The car runs great. I did not remove the heads as this engine is over 220,000 miles. I will be looking for a replacement to rebuild soon anyway. I did use cheap oil and filter for 2 days then changed the oil with good stuff. I flushed the coolant and washed the resevoir bottle as well. alot people tend to overlook that. Very good article. I did not have to jack the engine to remove the engine mount as it was not in the way. The front dampener or dogbone was.



William Green 5 years ago from USA Author

Hi TJ, since the oil was contaminated by the coolant, your camshaft was not being lub'd and the stress and over heating most likely cuased the Cam to fail (break)

William Green 5 years ago from USA Author

James if there is coolant in the oil and fluid is coming out f the intake gasket than your lower intake gasket is leaking. Sorry for the bad news.

james 5 years ago

Hi william i have a 95 lumina and there is no coollant in the cylinders but coolant is coming out the intake and its in the oil do you think its the intake gasket

Please help me out

TJ 5 years ago

I just had my head gaskets replaced as well as the intake gaskets. I was driving down the road and my 98 lumina died. I took it to a different mech. He said the cam shaft was broken. Anyone ever heard of this? Thanks TJ

JTW Jr 5 years ago

Just replaced the lower intake gasket on mine this weekend. Took me roughly 6 hours start to finish. Hardest part was indeed the rear lower valve cover gasket bolt. While I was in there I did install new plugs , much easier with the coil pack out of the way. I did not however remove the heads. Machine work in this town is ridiculous , when I did the 4 cylinder in my wifes Contour , machine work on the head cost $300. Car is now running fine , though I think we should each get a free whack at the Chevy Engineers for designing a intake gasket that requires you to remove some of the pushrods. What a poor design.

William Green 5 years ago from USA Author

Thanks Doug, I replaced all the lifter. Since I was that deep into it, I felt I might as well spend the extra money and not have to do it again.

doug richards 5 years ago

good article have done intake as well didn't have to pull any mount bolts (90 Cavalier) miserable job but went well make sure you have a good look at lifters I had a 4 that were "popped" replaced 3 ( ihad only bought 3) should have done 4 repaired 1 (cause didn't have a replacement

fashion 5 years ago

Informative article.......

William Green 5 years ago from USA Author

Thank you Brent

Brent 5 years ago

No need to remove the mount to access power steering bolt. Use a short 15mm socket, swivel, short (about 3-4") extension and ratchet. Remove the one mount bolt in the way and save a ton of time. This is why folks pay me.

William Green 5 years ago from USA Author

Dave you might have wrapped heads or cracked head. If you take the head have have it checked.

Dave B 5 years ago

You're right. (Un?)fortunately I will not be at their mercy as I try to fix a wicked coolant leak around the water pump. I changed the water pump twice now thinking I had a bad water pump. Runs cools as heck, except it is leaking :(. The only place I could figure it is leaking is at the head on cylinder 2 (the one left front). I am learning a lot but it's getting hard to be patient or have confidence.

William Green 5 years ago from USA Author

Good Job Dave B. You will never be at the mercy of the dealership mechanics again. I'm glad this helped.

Thank you for the compliment.

Dave B 5 years ago

Really appreciate the post William. It gave me the confidence to get in and do it for a 99 Lumina. The way you put it sounded just like my reasons to NOT do it, but I did with your help. It was not 'easy', took me 3 vacation days off work 2 weekends and 12 nights to do it but it runs wonderfully now. The only caveats I would put out there for anyone else are to be aware that a valve pushrod might jiggle out of place when you first start the engine. I was afraid that my 'help' put them in the wrong way and destroyed my engine. I re-mounted them and purred perfectly upon startup.

William Green 5 years ago from USA Author

WHen you took the heads off did you send them to the shop to be checked for cracks and warpage.

If you bought a junk yard motor did you pull the heads and have them checked at the shop.

Pandaman 5 years ago

I have replaced the head and head gaskets but I still an over heating problem, and the oil and water is mixing in the radiator and oil. I have replaced the lower intake gasket at least 5 times and I still have this problem even after changing motors. Can anyone tell me what I'm doing wrong or what it could be?

Bob 5 years ago

I removed my heads on my 3100 installed new gastets head and intake. When I put the eng back together it started but only ran for about 4 mins and shut down. I took a compressoin test and found 0 to 30 lbs compressoin. I can not ajust the valves so I removed the heads and had the shop check to see just how much they milled off. They said it was only 1,000 over the minumin. I am going to install head shims. I hope this takes care of my low compression. HAs any one else had this happen?

William Green 5 years ago from USA Author


If it is a Buick it is similar that is GM. Mercs are Fords different company different design, different procedures. Read your manual carefully.


wes 5 years ago

ok bill so i lied...its a buick. But regardless, have a good idea from your info, thanks and ill let you know how it goes!!!!!!

wes 5 years ago

thanks Bill...its actually on a mercury sable 3.0 6cyl. is that kind of the same setup as the 3100? i mean im very mechanically inclined just not so in depth as this will be. i know i can do you said...label,bag and pics.

William Green 5 years ago from USA Author


Just take your time. When you get tired and frustrated stop for the day. DON'T over tq the Upper Intake Manifold bolts. Label everything and take clear pictures. Bag everything.

Folow the shop manual and you should do fine.

Good luck let me know how it turns out.


wes 5 years ago

im fixin to replace the LIM gasket and have never done it before! after reading through this post...i feel real comfortable. is there any other insight or info for a "newby" getting ready to tackle this task? thank you!!!

stereos 5 years ago

it was interesting.

William Green 5 years ago from USA Author

Hi Scott,

What side of the engine are you looking from pass. or drivers. If it is pass side than it is the AIR solenoid valve, or the AIR Check Valve. If you are looking from the drives side than it would be the Manifold absolute pressure sensor ( under the coil pack) or the EGR valve. Your manual should help you out iD ing the sensor.

I would check your PCV connections it sounds like their might be a bad connection and the system is not properly sealed. That happened to me. As soon as I fix the connection the engine ran fine.

Hope this helps


Scott 5 years ago

Hi Will,

Can you please tell me what that sensor is, right above the left valve cover bolt??? I replaced intake manifold gasket the other day, and now engine surges and engine light is on?? Think I might have forgotten to plug a sensor back in. Got a 98 Malibu 3.1. Dont know what else it could be. Any info would be greatly appreciated!!

William Green 5 years ago from USA Author

Scott, thanks for the compliment.

Scott 5 years ago

Wow, I just did this job today before reading this article. Everything you mention was dead on accurate. Excellent article!!! A+++

William Green 5 years ago from USA Author

So far so good no bearing problems.

big blue 5 years ago

yeah, i think i'm just going to do that instead. But i heard that the antifreeze might mess up the main bearings, and that they eventually will go out, somewhere around 50,000 miles. so, how has your car ran?

William Green 5 years ago from USA Author

Big blue,

Dropping the pan and cleaning the oil pump would be an easy job, I had a foamy mixture that was coffee colored. I didn't drop the pan, but I flush the engine three times with cheap oil and cheap filters. I did not want to get into replacing the pan gasket and monkey around with the oilpump. I was outside and didn't want to risk getting dirt into the crank case. If I had access to a garage I would have dropped the pan and changed the pump.

I ran the engine about ten minutes each time.By the third flush, the oil was coming out as if it was right out of the bottle.

big blue 5 years ago

I have a question, how much of the substance did you find in your car? because the car we are fixing had a lot of the antifreeze/oil mixture in the engine. So do think i should take out the oil pan to make sure the oil pump doesn't plug, or how should i do an interior clean?

thanks for your time

William Green 5 years ago from USA Author

Doug, I'm glad this helped.

Thanks for the response.

Doug Caple 5 years ago

thanks for the insight...makes the job easy cause you are clear and also some short tear down was only 4 hours...and the kit was 100 bucks ...the dealer wanted

I am now replacing the gaskets...thanks again

William Green 5 years ago from USA Author

Alec swap the motor its a lot easier.

alec 5 years ago

got lots of coolant in the oil, engine was overheating previously, anyway got a motor in a 89 grand prix 3.1l also for $100 only has 150k on it 50k less than the one in my grand am that is broken, i drove the grand prix motor runs good and doesn't leak oil or coolant, i have a garage, was wondering if it would be better to just swap motors? it cant be much more work and will probably cheaper. the head gasket at the kocal gm dealer is $70

Sinna 5 years ago

Really great and clear instructions. Please let me know

that rear valve cove bottom passanger side bolt. Thank you so much.

Will88 6 years ago

what would be the cause of a clacking sound? wouldn't that warrant for more repairs?

William Green 6 years ago from USA Author


If the coolant is leaking into your oil change the oil regularly and top of the coolant. This should get you through until you have the funds to do the job. If you start to hear a clacking sound on start up do the job immediately.

I hope this helps

Will88 6 years ago

i have the lower intake leak on my 98 buick cetury, my question is, why dosnt the engine heat up with low coolant and oil? and wont it need to redline on the temp gauge to seaz up? i know this is an iminant problem and plan on fixing it asap, but funds are low at the moment and im curious as to prolong my engine life as much as possible before i can fix the gasket. thanks!

P.S. great article!

William Green 6 years ago from USA Author

Vern, the leak was at the mating surface of the lower intake and the head. I decided to take the heads off because the are aluminum and will warp very easily. Once I pulled the valve covers off and saw that mess, I realized I had better take the extra time and send the heads out to be checked. It turned out that the heads were warpped. If the oil had not been so badly contaminated or the the heads had been cast iron I would have left them in place. Good question thank you.

Vern 6 years ago

In all the years of doing these lower intake gaskets, I ask the question, Why did U take off the heads? Where was the leak?

DH 6 years ago

I own a 97 Lumina 3.1 with a little over 127k miles. I think my lower intake manifold gasket is leaking. I've had to top off my coolant 3-4 times in the past 6 months. Usually the resevoir has been empty and the radiator needing quite a bit as well. Today my low coolant light began flashing, before its always just stayed on, and now 2 hours after I came back from a 15 minute round trip to the store, my hood and engine are still radianting heat. I live in an apartment complex so doubtful I can do the repairs here, and already have spent $900 this year on other mechanical issues. I do an older Nissan Hardbody that I've kept as a backup but doesn't have A/C. Outside it's been running over 100 most of the day for the past few weeks and don't think it's going to make a comfortable drive. Anything else I can check before really deciding its the LIM? Replaced both radiator hoses in Jan. 2009 after one cracked. Radiator looks clean and no indications of a leak. I just don't want to sink more money in the Lumina with it's next to nothing value.

William Green 6 years ago from USA Author


I don't have the spec but DO NOT try to tighten the Manifold bolts to 120 lbs if your manifold is aluminum. You will sheer the bolt. It might be 120 inchs. IF you don't have the manual and you can't get one then use a regular wratch wrench and tighten until you fell it is sufficient. This is not the ideal solution but if that is all you have then...

Best of luck

Yaric 6 years ago

Im working on lumina myself without manual.What is the torque for manifold bolts? Is it about 89 in lbs and then 120 and outer bolts 18 ft lbs??

William Green 6 years ago from USA Author

Yes, if I know the answer, otherwise I approve the comment so that other may see it and help

lilpad4 6 years ago

Are you still responding to this?

Bill W 6 years ago

Is there a diagram somewhere that I can look up to see how the altanator goes back on. I seem to be missing how th brackets go. I know one goes to the top of the pleum. But where does the black bracket on the back go? There are a few more items I'm not sure where they go. Is there a web site to go to to get how this engine gets put back together. 3.1 Buick 1996 Skylark.

William Green 6 years ago from USA Author

Bill, on the 2000 Malibu 3.1 I had to take the pullies and the belt to get to the head bolts. It the only way to reach them.

Your top intake gasket is under the top secion of the manifold. Look at the first picture, the top assembly which has embossed on the top 3.100 SH, that is the upper intake manifold. When you took that off there was a gasket under each port. The lower intake manifold gaskets go on the heads I hope tis helps for a skylark.

BillW 6 years ago

I can not get the bracket off on the passenger side at back of engine. This hiding a head bolt under it.How do you get it off without taking the power steering and all the pulley's off? Or is this the only way. I have a 1996 Buick Skylark 1996 with 3.1 engine. This is the only thing holding me up from getting the back head off. Also, when you say lower intake gasket, what part is this under? Is the top gasket referred to as the actual head gasket? Or is that the lower intake gasket?

Alim Readi 6 years ago

If it is a 3.1 liter and it has the factory installed gaskets than you will probaly have the same problem at some point.

William Green 6 years ago from USA Author

Joe if there is no visable coolant leak, in other words a puddle on the ground, but you are getting a low coolant light you have a blown gasket. Which gasket is the problem? I can't say. You will need to run some test, or better yet bring it to the dealer and pay for the diagnostic. That will tell yoou everything that is wrong. Then fix it your self. This way you'll Know the job is being done right.

Good luck

Joe Phillips  6 years ago

I have a 2000 impala with the 3.4 It was running good. Till yesterday it started to run very hot. I'm constantly putting coolant in it lately. When I turn the car off I hear air and fizzing leaking somewhere. It sounds like it's coming from the heads. I'm having no issues tho..just a rising temp gauge but it won't overheat if I let the heater check engine light,no nothing, car runs like there's nothing wrong...jus a constant low coolant light and coolant leak but it leaks and never hits the ground. U

William Green 6 years ago from USA Author

Hi Dan,

sorry about the delay. The day job gets in the way but pays the bills.

Lifter tick is probably due to oil flow problem or underweight oil. Since the engine is torn down check your lifter to make sure their ok. If you have the cam out replace it. since Your this far into it, you might as well put in a new cam.

Once you have the engine put back together try a heavier weight oil that might take care of the problem.

dan 6 years ago

my problem is lifter tick .

the dealer replaced 6 lifters for $1000 but it still ticks.

I want to check oil pressure but I don't know where!Im also going to check the cam it's torn down already do you have

any other Ideas?? thanks.

Mose 6 years ago

Great hub Mr Green,

Very useful blueprint. Finished gasket job today. Few notes to add. The power steering pump removal can be done without rocking the engine. I used a real short (shortest you can find) 1/2 inch socket with quarter inch drive and universal joint. I still however had to remove the mount bolt closest to lowest pump bolt. If someone wants to do it this way, just be sure to replace the motor mount bolt as soon as you get the pump out of the way. You don't want the weight of the engine sitting on one bolt for an extended period of time. On the other hand however, if one does undo the motor mount and rock the engine, they can replace the serpentine belt at the same time, since it requires this procedure. Might as well, its only another 30 bucks give or take. :-) I got lucky. Mine was relatively new. Thanks so much.

William Green 6 years ago from USA Author


The only place I know of where you can get new bolts is from the factory. Check with a GM dealer see if they can order them for you.

William Green 6 years ago from USA Author

JFOL The intake valve can be seen when you look into the port openning of the head. So the rocker arm connected to the valve is the intake rocker place your rods accordingly. Sorry about the delay I have been busy with work

matt ardiere 6 years ago

where can i find new intake manifold bolts for the 3.1 engine?

JFLO 6 years ago

so are the longer pushrods the ones that go into the grooves on the head the ones behind the intake gasket like in picture 3

William Green 6 years ago from USA Author

Your push rods are two different lengths the short push rods are for the intake valves and the long push rods are for the exhaust valves if you mix these up your heads will be destroyed

William Green 6 years ago from USA Author

Jack,sorryI missed your comment. I would replace the head bolts along with the intake bolts just to be safe and if you have the money.

JFLO 6 years ago


jack jones 6 years ago

Head Bolt Torque Specs? is it nessasary to relace the head bolts? ive heard a few people say its recommended??????

Winson 6 years ago

The way I look at it, should be water goes into the engine compartment due to gasket leaking problem. Not so easy to clean up and drain out all the moisture trapped.

andy26 6 years ago

hello pat,

do this steps pull out the cylinder head and replace it be sure also to check or replace oil cooler , the cylinder head 99% has a little leak it may possible in water galleries use a genuine parts for repair

William Green 6 years ago from USA Author


Your problem could be any number of things, bad intake gasket was installed, a short in the electrical, old and cracked plug wires etc. Without actually looking at the car its hard to say. But since this only happens when it rains, I would check the plug wires for cracks. Moisture can get in through the smallest cracks in the insulation thi could be shorting the electrical. Check one plug wire at a time. If you have not purchased the repair manual for this car do so now it has a trouble shooting guide that can help you find the problem.

Good luck,


larry 6 years ago

have a 1996 lumina with 3.1 had intake gasket replaced now when it rains car misses bad till car warmes up in about 15 mins

William Green 7 years ago from USA Author

Hi Cobberman,

If your replacing coolant constantly and there is no sign of an external leak, you have a blown head gasket. Your description of the contents of the radiator is also a strong indication of a blown head gasket.

An average Joe can do a head job in his driveway. If you have never done a head replacement before, you can figure on the car being out of commission for about a 5 days. Doing this type of repair in an apartment parking lot is difficult. You have to drain and dispose of the fluids; you have to have all your tools handy and a place to store the parts as you remove them from the engine.

I would strongly suggest that you find a friend who will let you use their driveway for a week while you complete the repairs. The biggest problem is going to be the apartment complex. Management takes a dim view of people repairing their cars in the parking lot.

Before you begin repairs, check with the complex manager and ask him / her if you can do this kind of repair work. You don’t want to be in the middle of the job and have the complex manager tell you to stop and tow the car to a garage.

I hope this helps.

Good Luck


cobberman 7 years ago

Very informative.

My wife has a 2001 Lumina with the 3.1L and has had to add coolant for the past few months. We took it to a local shop for an engine light and jerky shifting and they said we needed a new O2 sensor and that it looked like someone took a $hit in the radiator. They didn't mention anything wrong with the transmission or the intake gasket but from your description I'm thinking that this might be the issue for the shifting problem. It also has trouble accelerating and has low power up hills. There is some brown muck in the coolant reservoir. I've since replaced the O2 sensor and the problem remains. Is this something that an average Joe can do out in an apartment parking lot?


William Green 7 years ago from USA Author

Glad it helps

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Gift Experts 7 years ago

Great Hub! My Friend 2000 Malabu is leaking intake is leaking for the second time. I think he got 60,000 on it. Thanks for the info.

William Green 7 years ago from USA Author

Hi Will,

I'm glad this article helped.

I applied a thin bead of RTV to both sides of the gasket.

Will 7 years ago

Very good and informative website! I'm in the middle of replacing the manifold gasket on my wife's 2000 Malibu and you've been much help. Question: You recommend RTV on the water jacket openings - Is this applied to both sides of the gasket?

Many thanks!

Amanda Green 7 years ago

Pretty informative and easy to read.

William Green 7 years ago from USA Author

Scoobydoo541: Don't sweat it it wasn't. It wasn't a dumb move you were just probably just tired and not thinking clear;y in the hot sun. Been there done that. Take a look at picture# 3 the intakes valves are on the inside of the heads the exhaust valves are on the outside. Look through the openings and you will see the intake valve that the rocker and push rod connect to.

I hope this helps.

scoobydoo541 7 years ago

help did a dumb move removed push rods with out marking putting new lifters and rods in 3.1 confussed on which is intake valve and which is exhaust i know short goes in intake and long goes in exhaust but which is which.

William Green 7 years ago from USA Author

Harry, I've never worked on a 96 and have not had to pull the engine on my 2002 so I'm at a lost to tell you where the mystery bolt is located. I'm sure you read the manual, but in some of those pictures it is hard to see the part.

It sounds like you have one more bolt on the bottom of the engine. I would suggest degreasing the bottom of the engine then put the car up on jack stands. Get at least two drop lights and illuminate the underside of the engine. Slowly go from one end of the engine to the other. use your hands to feel around in hard to see areas. Before you do this though, put back all the motor mount bolts you took off otherwise you will have major problems.

I wish I had a better suggestion. Good luck and don't give up. You will find it.

William Green 7 years ago from USA Author

Hi Pat,

The my temp gauge was with in normal range also. The milky substance on the fill cap, refilling the coolant, no leaks anywhere else strongly suggest a leak in the intake gasket where the block's water jackets connect to the intake manifold gasket.

Hope this helps

Harry Swope 7 years ago

hey i got a 96 monte carlo that has a front motor mount that i can't remove to get access to valve cover, exhaust and head any help in telling me where mistry bolts are hiding i did remove the top bolt

Pat 7 years ago

Hi, I have a question. I have a 97 Chevy lumina with a 3.1V6, with 105,000 miles. Last week I started to notice that I had to add about 2 quarts of 50/50 coolant mix every 3 days in my radiator, and this is the 3rd time I had to top it off. I see no leaks and there seems to be no white smoke coming out of the tail pipe. This morning I was checking the oil level with the dip stick and it was full to the correct level and the color looked normal, but when I removed the oil cap I found white milky foam on the cap and some in the valve cover. Engine runs smooth and does not over heat, Temp gage is always just under half. Elect fans work good and come on as they should, radiator, heater, and T-stat has good flow. The radiator cap has a little brown muddy build up on it and also in the neck of the radiator too. The missing coolant and the foam in the valve cover is a problem. My question is does this only look like a intake gasket problem. Note, I don't drive it anymore since discovering this problem. Thanks.

William Green 7 years ago from USA Author


Since you're that deep into the engine you might as well remove the heads and have them checked. This way you will know for sure that the problem is solved.

If you don't want to remove the heads then you could do a compression check before you begin the repairs to see if the heads are leaking. But, I would suggest that you remove the heads and get them checked. The heads are aluminum and can warp very easily. All the work you will have done to replace the gasket will have to be done again if the heads are warpped.

TED 7 years ago

do the heads need to be removed for this repair if only the intake is leaking

William Green 7 years ago from USA Author

Yabba Dabba- Do, thanks for the tips and the info on the GM claim.

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Yabber-Dabber-Do 7 years ago

I have done about 5 of these on usually the Malibu's and Buick Century's, takes me about 4-5 hours to do complete, with no returns. What most dealers or shops will not do because of cost is replace the metric head bolts, as this is a must on all these lower intake gasket changes. Bolts usually run around $75.00 for the set, but if you do not change them it is almost a sure job will be done again within 40-50K miles. While you got it down you might as well change them out as GM does recommend this, and before you even start make sure your torque wrench will read in nano's...12 nano's = 1 metric fp-very important. Yes, you can get paid back from GM, if you are the original owner of the vehicle and the vehicle has less than 100K miles on engine. Most owners will receive around $400.00 if you file a claim from a certified licensed mechanic which shows parts and number purchased, where purchased, copy of receipts, and repair ticket. Most of the claims were paid out around March of 2009 for many GM owners, as I received over $2400 from GM which I sent equal payments to all my customers who were part of this replacement. Anyone needing this information, I will forward the firm that sent us the money...Just go to my webpage if like to know where to file your claim, cannot promise you payment, but why not. Renovator Dave

William Green 7 years ago from USA Author


If it is a 3.1 liter and it has the factory installed gaskets than you will probably have the same problem at some point.

P-O 7 years ago

Thanks for the information! I just have a question, is this a common problem on the later 3.4 liters engine? The car i've got is a chevrolet transport thats made 1999. I can see on the pictures that the constuction is the same on my engine. Hope you can excuse my bad english..

dreamcc 7 years ago

information is very clear. good and understandable explanation. super-topics. Thank you for sharing a very nice web site.

William Green 7 years ago from USA Author

HI Mike,

Yes I used Felpro gaskets on the intake and the heads. A placed a small bead black RTV around the openings to the water jacket and added a tube of alumiseal to the coolant.

Mike 7 years ago

Awesome, what type of gasket did you use? Felpro? Please email me at I have a few more questions for you.


William Green 7 years ago from USA Author

Well Mike, so far so good. I'll find out after I drive to GA and back.

Mike 7 years ago

Great article! How is the lower intake manifold gasket holding up now since you have replaced it yourself?

roman 7 years ago

by the way, the zip lock bag idea. very very good for the ameteur mechanic. It's very depressing when you see left over bolts.

Roman 7 years ago

easy off works with ovens in much the same way it does in the oven. In the oven you let it set for 20 minutes room temp. you can do the same to the intake if you like. rather than letting it set for a few hours just do it twice. it should only take an hour and a half. great hub

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Gin Delloway 7 years ago

great hub!!! I like it!

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earnestshub 7 years ago from Melbourne Australia

This is all the info needed, thanks.

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