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Symptoms of a Bad EGR Valve

Updated on October 27, 2015
Dan Ferrell profile image

Dan Ferrell writes about do-it-yourself car maintenance and repair. He has certifications in automation and control technology.

EGR valve passages plugged with carbon deposits.
EGR valve passages plugged with carbon deposits. | Source

The same symptoms that indicate a bad EGR valve can also indicate problems in other parts of the system. For instance, you can confuse engine performance problems stemming from a bad EGR valve with problems caused by failures in the spark plugs, the spark plug wires, the fuel filter, the fuel pump regulator, and various engine sensors. So, if you don’t do your troubleshooting, you may end up replacing parts unnecessarily and wasting time and money.

To recognize the potential signs of a failing EGR valve, it helps to know a little about an EGR valve: what it does, what it might look like, and how it works inside the combustion chambers or cylinders.

If you're already familiar with the EGR system, jump to the section below on “Symptoms of a Bad EGR Valve.”

Table of Contents

I. What the EGR Valve Does
II. Types of EGR Valves
III. How the EGR Processes Exhaust Gases
IV. Symptoms of a Bad EGR Valve
V. Troubleshooting

Source

I. What the EGR Valve Does

The EGR valve is a small component designed to allow the flow of exhaust gases into the intake manifold in controlled amounts. As such, it's a simple valve that closes and opens as needed.

The EGR valve has one single job to do, regardless of the system configuration, type of control and number of sensors: that is, to either open and direct exhaust gases into the combustion chamber, or to close and keep them from entering.

Whenever you start the engine, the valve comes alive and waits in a closed position, blocking the flow of exhaust gases.

Once the engine reaches operating temperature and speed increases, the valve — either through vacuum or electronic control — gradually opens, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. If you slow down sufficiently or come to a stop, the valve gradually closes and blocks the flow of exhaust gasses. And the process continues for as long as the engine is running.

After you shut off the engine, the EGR valve closes and remains in that position.

II. Types of EGR Valves

Gasoline and diesel-powered engines have various EGR system designs. Vehicles on the road today may use one of six different valve configurations.

On older vehicle models, you'll recognize the valve as a round, thick, metal disc about three inches in diameter, usually towards the top of the engine and on the side.

On these older models, a small-diameter vacuum hose operates a basic EGR valve. The hose connects the top of the valve to the throttle body or carburetor. The valve's metal disk houses a vacuum diaphragm, spring, and plunger.

Later models come equipped with electronic-vacuum EGR valves inside a small block or cylinder. The valve works the same way as in older models, except that an electronic EGR position sensor communicates with the car's computer for better control. You may see electric solenoids connected through vacuum lines to the valve as well.

Newer vehicle models use electronic EGR systems that may include additional components, even a digital valve that eliminates the need for vacuum control altogether.

A more radical design, implemented in a few models, was the replacement of the valve with EGR jets at the bottom of the intake manifold.

Some newer high-efficiency engines, for example those with variable valve timing (VVT), don't even use an EGR system.

Different Types of EGR Valves
Vacuum-controlled EGR valve
Back-pressure EGR valve
Electronic vacuum-controlled EGR valve
Digital EGR valve
EGR jet (in place of EGR valve)

III. Processing Exhaust Gases

The outside air picked up through the engine's intake manifold contains close to 80 percent nitrogen and 20 percent oxygen, along with small amounts of other elements. When outside air combines with the fuel and ignites in the combustion chamber, temperatures can reach above 2500o F (or 1370o C). Combustion at these temperatures burns the usually inert nitrogen gas, creating oxides of nitrogen (NOx) gases, which cause air pollution and human health problems.

However, when the burned exhaust gases are introducted back into the combustion chamber through the EGR valve, extreme temperatures decrease, inhibiting the formation of NOx gases.

Source

IV. Symptoms of a Bad EGR Valve

An EGR valve can fail in two ways: It can be open all the time, or it can be closed all the time.

If the EGR Valve Sticks Open:

This will cause a continuous flow of exhaust gases into the intake manifold. You'll notice one or more of the following symptoms:

  • A rough idle upon starting the engine (that is, when the engine is cold) and sometimes at a stop light or while looking for a spot in a parking lot (that is, at low engine speeds in a warmed-up engine).
  • Stalling when the engine idles.
  • Increase in fuel consumption.
  • A slight — or strong — fuel odor while operating the vehicle, because of the increase in hydrocarbons leaving the tailpipe (see the next symptom).
  • Emissions test failure. When the engine is running at low RPM, lower temperatures in the combustion chambers prevent all the fuel from burning, so the flow of unburned hydrocarbon gases coming out of the tailpipe increases significantly.
  • The Check Engine light (or Malfunction Indicator Light, MIL, depending on your model) illuminates on your dashboard.


If the EGR Valve Sticks Closed:

This will permanently block the flow of exhaust gases into the intake manifold. You'll notice one or more of the following symptoms:

  • A pinging or tapping noise coming from the engine at low RPM (at speeds higher than idle). The noise is the sound of early ignition of the fuel when it meets high temperatures.
  • Loud detonations. A second ignition can happen after the normal ignition, and the two can combine with enough power to potentially cause serious engine damage.
  • Your car fails the emission test. High temperatures in the combustion chamber allow the excessive formation of oxides of nitrogen, which are released through the tailpipe.
  • The Check Engine light, or Malfunction Indicator Light (MIL), illuminates on your dashboard.

V. Troubleshooting

Are the symptoms above a sign of EGR problems?

Not necessarily.

An increase in hydrocarbon emissions isn’t necessarily caused by a stuck-open EGR valve. Problems in other systems may cause this same symptom as well: a leaking fuel injector, bad ignition timing, bad cylinder compression, bad oxygen sensor, or other problems.

Similarly, an increase in NOx may be caused by a vacuum leak, a clogged fuel injector, low fuel pressure, a leaking head gasket, or other problems.

A rough idle may be caused by a faulty ignition coil, a vacuum leak, or an ignition system problem.

Because these symptoms vary and be caused by different issues, don’t hesitate to troubleshoot the EGR valve and other system components to try to narrow down the problem. This article, How to Test an EGR Valve, gives a series of troubleshooting procedures on vacuum and electrical vacuum-controlled EGR valves, and will help you find out if the problem is your EGR or something else.

Also, because cars with electronic EGR valves will have a Check Engine or MIL light on the dashboard, in these cars you can find out what engine system malfunction triggered the light. With an aftermarket scan tool, you can pull the trouble codes from the computer's memory and see what system or components are causing the problem. Then, you can try to find the fault with the help of the vehicle repair manual for your particular car make and model.

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    • Dan Ferrell profile image
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      Dan Ferrell 4 minutes ago

      Hi Sean,

      I doubt a bad EGR valve can cause a no-start. You may have a problem in the starting, fuel or ignition system.

      Good luck.

    • profile image

      Sean 29 hours ago

      Could a bad egr keep my 04 Chevy impala from starting?

    • Dan Ferrell profile image
      Author

      Dan Ferrell 4 days ago

      Hi Olivia,

      The check engine light is blinking because is warning you that a fault in the engine may cause serious damage to the catalytic converter. You may have too much unburned fuel going through the exhaust system or possibly oil. That's why the smoke you see. You need to look into the issue as soon as possible before it turns into a very expensive repair.

      Good luck.

    • profile image

      Olivia 4 days ago

      Hello Dan,

      My 98 Volvo v70 is smoking under the engine and the check engine light is blinking. Also seems to have a rough time going above 30 mph but the roughness goes away once I get above 40. It seems the go into limp mode when it's in the 30s. Does this sound like egr valve issues? Thanks

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 days ago

      Hi Brian,

      It sounds more like you got a fuel system issue. Have you checked the fuel pressure regulator, pobbily a bad pump?

      Try to get the DTC (trouble codes) from the computer and see what you got. That's a start.

      Good luck

    • profile image

      Brian 5 days ago

      Hi Dan,

      Can a bad ERG value be causing my 2004 Kia Rio to loose power intermittently during acceleration? This situation repeats itself--I lose all power, then 8-10 seconds later it comes back, then power loss again. Thanks.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 weeks ago

      Hi Erick,

      A bad egr is not likely to cause a fault in the TPS but the sensor can prevent shifting.

      Good luck

    • profile image

      Erick 5 weeks ago

      Can a bad egr trigger a bad throttle position sensor and make the car not shift?

    • profile image

      Gordon darragh 5 weeks ago

      I've just changed the egr valve on my mk7 transit and it's caused the plastic oil filter housing to crack twice

    • Dan Ferrell profile image
      Author

      Dan Ferrell 2 months ago

      Hi Scott

      Check to see if any vacuum hoses or connection was not properly replaced, or some screws left a little loose.

      Good luck.

    • profile image

      Scott 2 months ago

      Hi Dan

      I have a Hyundai Santa fe 2008 diesel. First it was stalling intermittently especially when slowing down or stopping. Mechanic replaced cam shaft sensors and serviced EGR. It doesn’t stall anymore. But it now seems to hesitate on acceleration it feels like its choking a bit when you start to accelerate.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 2 months ago

      Hi AE,

      Have you checked the vacuum hoses. It seems something didn't get properly connected.

      Good luck

    • profile image

      Adam Elvis 2 months ago

      Hi Dan,

      I have a '06 Mazda Speed6 with 125,000 Kim's. I just replaced the EGR Valve and now my car has less power at higher rpms in 1st,2nd &3rd gears. When I put the peddle down, I hear a slight whistling sound ( like a hole in the muffler). All other components in my car are fine. What do you think the issue is with the loss of power and whistling air sound?

      Thanks,

      Adam.

    • profile image

      richard wright 2 months ago

      I have a 2002 Mazda millennia and it won't start it has fuel pressure and spark and won't start even with starting fluid any idels

    • Dan Ferrell profile image
      Author

      Dan Ferrell 2 months ago

      Hi Ben

      If the dies soon after it starts, check the fuel system, does you have enough fuel pressure, when was the last time you changed the fuel filter, do you check that all vacuum lines are properly connected and in good condition.

      Start with the basics, and scan the comoputer memory for trouble codes. A TC may give you a good direction at what the problem might be. You may have a problem with one or more sensors (camshaf or crankshaft problems?).

      Good luck

    • profile image

      Ben 2 months ago

      Hi Dab

      My car starts but cannot idle and the plugs do not fire up.

    • profile image

      Cheryl 2 months ago

      If the EGR valve is faulty would it make a loud noise when driving...like a sirene

    • Dan Ferrell profile image
      Author

      Dan Ferrell 3 months ago

      Hi Tch,

      Have you checked for trouble codes (scan the computer memory). You may have a problem in the fuel system. Sometimes it's some thing as simple as a clogging fuel filter that is not allowing enough fuel flow to reach the engine when demand increases. Go to an auto parts store to have the computer scanned. They'll do it for free.

      Good luck

    • profile image

      Tawanda chibaya 3 months ago

      My dci1,5 is cutting off while im driving

    • Dan Ferrell profile image
      Author

      Dan Ferrell 3 months ago

      Hi Matt,

      It doesn't seem to be EGR related if it is happening in some degree when cold or hot. It seems have an issue with a sensor that is affecting the fuel system (coolant temp sensor, TPS, etc) or a problem in the fuel system itself. Have you tried scanning for codes, this might point you in the right direction.

      Good luck.

    • profile image

      Matt 3 months ago

      Very helpful guide thanks Dan.

      Currently having a problem with my 1.6 TDI Seat Ibiza, seems very underpowered lately to me (as in hesitation). Most obvious when the engine is cold. A good example would be when I'm pulling out on a roundabout and I'm really having to push down on the throttle to get a response from the car.

      Another symptom I'm having is that sometimes when braking hard (for instance approaching traffic lights) the revs will drop and fluctuate, sometimes causing the engine to cut out completely.

      The issues seem to be heightened during DPF regenerations which are happening on an almost weekly basis lately. Do you think the problems I'm having could be related to the EGR valve?

      Many thanks

    • Dan Ferrell profile image
      Author

      Dan Ferrell 3 months ago

      Hi Lynn,

      Yes, you may have an intermittent problem with the EGR valve, probably not opening as it should, or carbon deposits blocking the passages.

      Good luck.

    • profile image

      Lynn 3 months ago

      I have a question...my van seems to want to stall out but not when I first start it. It does it when I am cruising at a steady pace, whether it is 30, 40, or 50, etc, mph. My check engine light goes on and off periodically and I do have the EGR code when it's on. Could this be the problem?

    • Dan Ferrell profile image
      Author

      Dan Ferrell 4 months ago

      Hi John,

      If the valve sticks close, engine temperature will go up, but it's likely you'll hear knocking (detonations).

      The most common failure is for exhaust passages to clogg with carbon buildup. You can remove the EGR valve and check the ports on the cylinder head and underneath the valve. Use carburetor cleaner to remove buildup. Just be careful with electronic circuits, if yours is an electrical type.

      Good luck.

    • profile image

      John 4 months ago

      Can it cause your car temperature gage to go up and down like it want to run hot

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi Oscar,

      The fact the you can smell gas points more to a reach air/fuel mixture. Have you check for possible leaks? Have you scan the computer? You may have some pending codes that can point to the problem.

      Good luck

    • profile image

      Oscar 5 months ago

      My 2000 firebird smell alot of gas, when I accelerate hard it throws a cloud of smoke but if I don't accelerate hard it won't smoke. Could this be the egr valve

    • profile image

      uriah 5 months ago

      stay away from the refuge church in homer as it is a refuge for gangstalkers also.

    • profile image

      Ross Gilbert 5 months ago

      Hi just to update in case anyone has a similar experience to myself. My 2012 Mark3 ford focus was puking coolant, running quite well! Very very Slightly ruff. The coolant was bubbling but no oil in coolant or coolant in the oil. Tried pressure test for leaks couldnt find anything. Didnt have the equipment to pressure test the cylinders. Tried replacing the EGR Cooler as this was the only other thing that could throw exhaust gasses into the coolant. No Joy.

      It was the head gaskett. Had it repaired today at a cost of £819 but included new timing belt, water pump. Flush and new coolant and oil filter change and oil so overalls happy with that.

      Thought id give an update as i was searching the Internet for similar cases. Kept been told that that it wouldnt be the head gasket as they dont go on the 1.6tdci.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi CL,

      When the EGR valve sticks open it'll cause a rough idle, even a stall. If it sticks close engine temperature will rise. While driving, this will cause detonations --you'll hear a knocking coming from the engine while driving.

      It's common for buildup to block EGR valve passages, so they require cleaning from time to time (depeniding on your driving patter and maintenance, about three or four years). But they can go also bad and will need replacement.

      It's possible to test the valve before replacement. https://tinyurl.com/kjt8lsz

    • profile image

      Christina Lee 5 months ago

      Can a bad EGR Valve cause the car to completely die.stop running while driving? Are they to be replaced OR cleaned?

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi airnewzealand15,

      I've heared of this problem on some models. Don't know if yours is similar. but the small gears that connect the meter to the transmision may wear out and you see what you describe, the pointer goes all over the place or just dies. If your particular model is fully electronic you might be dealing with a fault in the control module.

      Good luck

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi Gilbert

      Have you noticed a rough idle or some performance problem before. You may be dealing with a clogging fuel filter or bad fuel pressure. When was the last time you replaced the fuel filter? Check the fuel pressure as well.

      Good luck.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi JM,

      Did you check the injector, is it firing? You may be dealing with a clogged injector. Test the injecotr's coil resistance. Unplug the electrical connector and use a meter. You should get around 11Ohms, otherwise is no good. If it test find, you may need to remove it and see if it is acutally spraying fuell

      Good luck.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi MK,

      Don't remember much about this model, but I know that on the aztec you have little room to move aroun. If yours is similar, try moving the automatic trnamission filler tube out of the way by removing the securing nut. In most cases you don't need a special tool. Then just remove the mounting bolts securint the valve (and perhaps the pipe).

      You can do a visual check around the valve to see what you need to remove.

      Good luck

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi Cam,

      It would be a good idea to test the EGR first, You can use a hand held vacuum pump. Follow the steps here http://tinyurl.com/lus7a96

      If you feel comfortable doing your own tests, get the vehicle repair manual for your model. The EGR valve test is not too complicated and you can do it at home.

      If the shop does any work, you need to get some guaranty that they will make the correct repair.

      Good luck.

    • profile image

      Cam 5 months ago

      Hi. This article is very helpful.

      I have a 09 Chrysler Town and Country. The check Engine Light is lit up. After the van gets warmed up, it shuts down if I have to come to a complete stop (at a light or stop sign) but goes back to normal after I have to restart it and get moving again. Took it to one shop.. They said oh yeah, it's the torque converter and he did say it's the EGR. But didn't say that's what's causing the stopping. HE changed the torque converter. Problem still occurred. Took it back, now it's the Transmission and the EGR. DO you think replacing the EGR could be the quick fix for this problem do I really need to change both the transmission now and the EGR? 09' Town & Country w/ 160k miles.

      Thanks for any suggestion you are able to provide.

    • profile image

      airnewzealand15@icloud.com 5 months ago

      Thanks for this! I have just fixed the broken cog wheel in my egr valve on my golf GT mk5, and cleared the check engine light, but now I've just noticed that the live reading of km/l is all wildly inaccurate and sometimes just goes to --.--. It will go from 4 up to 50. Have you heard of that before. Thanks so much.

    • profile image

      Marlys Knaffla 5 months ago

      I called about the egr how to remove it and do you need a special tool to get it out my 2003 Pontic agree?

    • profile image

      John Medina 5 months ago

      My mini turbo has 124'000+ miles it is a 2008 clubman I replaced all plugs & coils to include the air flow intake sensor & is still misfiring I can't find the egr valve location or replacement part

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi RG,

      it wold be a good idea to locate the fault first (Compression test). If you are dealing with a blown head gasket, the fix may be a little expensive.

      The test results can give you an idea how much you'll need to spent in repairs.

      Good luck

    • profile image

      Ross Gilbert 5 months ago

      Dan, Wow thanks for the fast response.

      So it would be worth changing the EGR and cooler unit first just to eliminate it.

      I can source a second hand one from my breakers from a running car with 30k on the clock for £60.

      But you are saying if the cooler was broken this could potentially pressurise the reservoir tank with combustible gasses.

      The gasses/bubbles appear almost imediately into the reservoir on starting the engine.

      I know i could also do a compression test but I dont have a diesel one - may buy one.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 5 months ago

      Hi RG,

      On a fairly new model like yours, yes it's very rare to see a gasket failure like this, unless the engine overheated over a period of time without you becoming aware. Rare but it could happen.

      If the EGR valve stick closed, it is possible for the engine to overheat. If that happened and your driver pattern involve short trips of a few miles at a time, (as opposed to highway driving commute driving) but long enough for high heat to do its job, that could explain somehow the failure. You can also be dealing with a cracked block, cylinder, intake could happen as well.

      Good luck

    • profile image

      Ross Gilbert 5 months ago

      I have a ford focus 2012 1.6 tdci and I am having issues with exhaust Gasses in the coolant reservoir (obviously after a few miles coolant pukes out the reservoir due to pressure).

      Its had a professional sniff test and its exhaust gasses so Gasket related.

      I know this is Head Gasket symptoms but I cant tell you how well the car runs with no smoke or contaminated oil in coolant and coolant in oil. Also been told that head gaskets are a rare occurrence on these. So i am scratching my head somewhat.

      Could a faulty EGR and cooler cause exhaust gasses in the coolant reservoir??? And the symptoms I am having??

    • Dan Ferrell profile image
      Author

      Dan Ferrell 6 months ago

      Hi Gilbert,

      If the egr valve sticks open or leaks it certainly will cause your car to stall and make it hard to start. However, if the engine refuses to start now check the spark and fuel. A clogged fuel filter will prevent your car from starting. When was the last time you replace it? Usually you can check it by removing the filter and blow through it in the direction as fuel flow. You'll notice air difficult going through if it is clogging. Don't forget to scan for codes. It can give you some direction.

      Good luck.

    • profile image

      Gilbert 6 months ago

      Hi Dan.

      The other day I was driving my vehicle. No problem. As I inclined up a ramp my car shirt off and now doesn't want to start. I wanted to know could it be a bad egr valve or the fuel pump and or filter. You can clearly heat the fuel pump working but would it be the filter that maybe clogged.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 6 months ago

      Hi Rich,

      Glad to know you finally solved the problem. And yes, it's hard to find reliable shops out there,

      Good luck

    • profile image

      Rich 6 months ago

      Hi Dan

      Thanks for ll of your advice. What happened to me with this vehicle is not nothing short of "criminal". Turns out that my rear motor mount was completely destroyed. This is after a so-called mechanic said he checked it and changed it. You cannot even make this up.

      How do I know this now? I decided to take the vehicle to someone else for another opinion and low and behold the motor mount is completely shot.

      If he did not take me into the shop and show it to me I would have said what are you talking about it was just changed. Talk about getting ripped off!

      I am replacing the mount today and will deal with the previous mechanic via the BBB.

      At least my vibrating van is quiet now.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 6 months ago

      Hi Rich,

      Changing maintenance items is not a problem, you still have to do those, but the ignition coil could've being checked before changing. Also, you can check spark plug wires with a Ohm meter. Other items to keep in mind: fuel filter, fuel injectors, fuel pump, Check schedule maintenance and troubleshoot as necessary, before replacing.

      Good luck

    • profile image

      Rich 6 months ago

      Dan

      Changed EGR valve, cleaned out all deposits, changed air filter, changed motir abd transmission mounts, changed plugs and coils. Idle is still rough.

      Next I plan to do a throttle body cleaning.

      The money pit!

    • Dan Ferrell profile image
      Author

      Dan Ferrell 6 months ago

      Hi Rich,

      The motor mounts was a good guess, but if you changed them and didn't fix the problem, check the universal joint for wear or damage. That can also cause the vehicle to vibrate.

      Good lcuk.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi Rich,

      You may be dealing with a vacuum leak (check all vacuum hoses), or possibly an ignition system failure - when was the last time you checked-changed the spark plugs, spark plugs, - also check the airfilter, if over two years, change it; also the fuel filter. Checking these items is a good start.

      Good luck.

    • profile image

      Rich 7 months ago

      2001 Honda Odyssey with a rough idle while stooped at a traffic light. The van vibrates into the steering wheel. Frustrated!

      Changed motor and transmission mounts. Could the EGR valve be bad? No engine light codes found at shop. In fact all clear on code checks.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi DD,

      From what you describe it seems there's an exhaust or vacuum leak. Hard to tell, but if the engine doesn't improve at any speed range, I don't think it is the EGR valve. Check for leaks and check the exhaust manifold and gasket. It wouldn't hurt to scan the computer as well. You may have a pending code that hasn't "surfaced" yet.

      Good luck.

    • Don Dragodon profile image

      Don Dragodon 7 months ago

      I have a 2001 Ford Focus ZX3. It has bee sounding rough since I got it. It sounds like I'm driving a muscle car with a head cold. It shakes and vibrates while I'm driving and even more when I'm stopped. On some rare occasions it has stalled out on idle. I lose horsepower at times, especially going up slight inclines and has terrible gas mileage. I tried fixing several things including a new timing belt, flex pipe, and a new coil pack, but nothing has changed. A friend of mine just recently mentioned the EGR valve. Could these symptoms point to that and how much does a mechanic usually charge to check the valve? The car starts up fine, but loud, and the check engine light has not come on (yet).

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi Cass,

      You need to have the EGR tested first. The valve could be sticking. Also, a sensor can be sending the wrong signal and causing the computer to wrongly lean the mixture when it should not.

      Good luck.

    • profile image

      Cass 7 months ago

      I have a 99 Buick lesabre that's check engine light is on. The fiance took the car to guy with a reader and he told her it was an egr valve code. After its warmed up and been running a while it dies when you slow down but it stays right up afterwards, but the only way to keep it running is to keep foot on the gas even when coming to a stop, any ideas would be appreciated before I buy a valve and replace it. Thank you.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi Larry,

      If the EGR valve sticks open, it'll cause a rough idle and likely to stall. If you already got a EGR trouble code, you should check it, it might be causing your no start unless you also got some starting relating issues.

      You can test the valve at home:

      https://axleaddict.com/auto-repair/How-to-Test-an-...

      Good luck.

    • profile image

      Larry 7 months ago

      Would faulty EGR valve cause van not to start? 2007 Chrysler Town & County. We had the van hooked up to a computer a couple of weeks ago and the code returned an EGR Valve problem. We did not have it fixed at that time.

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi Andre,

      If the EGR sticks closed, it'll cause the engine to run hot. So it is possible the ECU is shutting off the engine. However, the ECT should signal a higher than 200F for the ECU to consider the situation critical. Otherwise the engine should be within temperature range.

      You should check the ECT circuit voltage using a voltmmeter. Also check the connectors for loose wires and wires condition.

      Also, it's possible for you to check the EGR valve.

      https://axleaddict.com/auto-repair/How-to-Test-an-...

      Did you ask the dealer about possible TSB (technical service bulletins) on your model?

      Good luck

    • profile image

      Andre 7 months ago

      Hi Dan,

      I have 2010 VW Routan, 6 cylinders, 4L with about 195000km.

      Last two months I have a problem with car shutting off without any warning or lights on dashboard. My car mechanic friend plugged his computer and there was no error code on it. He decided to change crankshaft sensor. After that, no change. We plugged computer in again and took it for a ride. We got ECT error. We replaced this sensor, and , no change. It seems that when I start the car ECT info is in black, it changes to red about 130 degrees Fahrenheit. After talking to my friend we decided to take it to the dealer. Car shut off just 5 km before I reached dealer. I explained everything to them and ... they couldn't find any error codes neither. However they told me that they had similar issue with different car and they replaced EGR valve.

      Would faulty EGR valve cause car to shut off on the road? As I mention that happen without any warning, sometimes when I just start to drive (cold engine) sometimes when I am doing 100km/hr on highway (hot engine). No warning light on dashboard, nothing, just shuts off. Any idea?

      Thank you

      Regards

      Andrzej

    • Dan Ferrell profile image
      Author

      Dan Ferrell 7 months ago

      Hi asrar

      It seems your computer when into "survival mode". it probably detected one or more sensor going out of range. Then it put the transmission in single gear for safety. You should take your car to the shop to have them scan for trouble codes and diagnostic. And it should be a priority.

      Good luck.

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      Dan Ferrell 7 months ago

      Hi J,

      Yes, it could be. If the EGR sticks open, it could stall the engine at idle.

      But there are a number of sensors and issues that may cause this symptom as well. Have you try scannin for trouble codes?

      Even if you don't see the check engine light come on, you could

      have some pending codes that might help you.

      Good luck.

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      Jesse 7 months ago

      Hello, I'm having issues diagnosing a stalling issue with my 91 full size blazer with the 350tbi.

      Everything ignition wise have been inspected or replaced, fuel pressure is good and injectors are good. When at idle it will slowly lose rmp and die, when placed in gear or stopping at a red light it will stall also. Could it be an EGR issue? Thanks!

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      asrar 7 months ago

      Hi dan

      I have vw passat diesel when i am traveling at 70 mph and going up hill when i press gas paddle the engine goes in to limp mode.

      I have cleaned the egr valve but no change can you help.

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      Dan Ferrell 7 months ago

      Hi Susan,

      Buildup can block proper operation for the IAC (idle air control) solenoid, and mislead the car computer about the angle of the throttle valve (plate) position. Have your mechanic remove the IAC and check for buildup and torubleshoot the IAC to make sure it is working as it should. Problems with the EGR valve itself may show up at idle or at higher speeds. If necessary, have it checked too.

      Good luck.

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      Susan 7 months ago

      I have 1997 Civic. Alternator went bad and was replaced, along with the battery. A week later, threw a code of P1509 (air idle control sensor), and a few days later started bucking while driving. Had distributor cap, plugs, wires replaced and ran okay for a few days, then started bucking again. Next fuel filter replaced, and it was good for the repair shop, but started back up again later that day. Was hoping it was bad gas, but not so sure now. Started to buck after about 10 minutes of driving, hesitates/bucks when accelerating from a stop, bucks if I let off the gas, and sometimes just shakes when driving. The idle didn't start acting up (racing) until a couple weeks into this problem. My tach stopped working, maybe when it threw the code originally, but not sure. I've put fuel injector cleaner and dry gas in the last two tanks of gas (am still on first tank of gas after fuel filter replaced). Could it be the air idle sensor causing this, even though the symptoms happen mostly while I'm driving, or could it be ERG, or something else? Thanks!!!

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      Dan Ferrell 8 months ago

      Hi Cameron,

      From what you describe, it seems you got a cold start problem. Have you checked for any DTC (computer trouble codes)? Go to an auto parts store and have them get the DTCs for you.

      I don't think the cat will give you this cold-start problem. You'd loose power if it was clogged.

      Good luck.

      ------

      Hi AM

      Have you checked the MAF sensor - although it shouldn't fail only on humid days, give it a try. Make sure it's clean and the harness and wires are in good condition.

      Good luck

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      Anthony Maragni 8 months ago

      Your information is very helpful my problem is 02 Chevrolet Silverado 4.8 when wet or damp misfire occurs clears up after 10 to 20 minutes new wires and plugs and coil packs HELP I am lost

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      Cameron 8 months ago

      I have a 2006 civic EX 270,000 on the stock cat it seems. The motor was swapped and has around 150,xxx. On random mornings I start the car with a rough idle and when given gas disappears immediately. While cruising in gear until it's warmed up sufficiently if I back off the gas all the way I get almost a studder sound coming from the motor, when the motor has been driven for x amount of Miles it goes away. Normally if the car is started within a few hours of its last shut down it will start with no vibration. Some days it starts completely normal with no vibration. I have a test pipe (in a state with no emissions) and while I take the stock cat off I believe this will be the first place I look further. If it is dirty as can be then I will clean it and replace the plugs. If the random rough idle continues where do I go from here?

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      Dan Ferrell 8 months ago

      Hi DJ,

      If you've noticed this problem at idle most of the time, yes it could be a problem with the EGR valve (or carbon build up at the ports, for example). But you can also have other issues:

      * Idle speed valve , carbon buildup at passages (remove and check) or a device malfunction.

      * MAF (have you check for a dirty valve?, possibley you'll need a scan tool to check operation but consult the repair manual for troubleshooting checks for your MAF.

      * It could be something as simple as a clogging air filter - when was the last time you replace it (evey one or two years is the recommended)

      * check for possible vacuum leaks - at high speeds a small leak won't give you trouble but you'll notice at slow speeds.

      * Also, check the throttle position sensor (TPS)

      https://axleaddict.com/redir/?redirectUrl=https%3A...

      I would start with the most simple items and don't forget to scan your computer for possicle trouble codes. If you don't have a scan tool, your local auto parts store can get the codes for you for free.

      Good luck.

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      Dominique jones 8 months ago

      Hi! I have an 2005 chevy cobalt .

      My car is doing the same thing! Every time I stop or slow down it just dies out and tries to start itself up again! The car has been in the shop 3 times and everyone keeps guessing , I've had the spark plugs replaced , the fuel filter , and the battery recharged cause sometimes it just dies and it won't take a jump . I've spent so much unnecessary money it's ridiculous. I don't know what to do . Do you think it's the EGR Valve ? Any advice will help please and thank you !

    • Dan Ferrell profile image
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      Dan Ferrell 8 months ago

      Hi Tazz

      Usually when a gas pump or ignnition modules is going it'll show those same symptoms. After the car stalls, you need to let the pump or ignition module to cool and then it'll start. But seems like you can start the engine right away. Have you checked the neutral safety switch for adjustment or wear, the connection at the ignition, even something as simple as a clogging fuel filter can be causing this. Also, check the battery cables at the terminals. If some threads are broken, vibration eventually may put a lot of current resistance.

      Good luck.

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      Tazz William's 8 months ago

      I have a 99Sebring the car runs great,but Theres one problem thats driving me crazy. The car starts and drives but after a short time it will stall out. Put it in netrual or park and it starts right back up and down the road you go. Sometimes a few blocks sometimes few miles. Them it does it again throw it in neutral and it starts right back up and away you go. Mostly at stop signs or into slow curves. I've checked everything I can think of. Please help Whats wrong with this thing??

    • Dan Ferrell profile image
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      Dan Ferrell 9 months ago

      Hi Arthur,

      Sorry for the late answer. I was having issues with my browser and didn't see some of the posted comments. The short answer to the issu is: it depends on the particular failure of the EGR. Did you try to erase the code after decarbonizing the valve passages? Did it come back on? If so it is a good idea to test the EGR. You have an electronic device. The vehicle repair manual for your particular car may show you the way to troubleshoot the valve and related componets. You can buy an aftermarket copy online, try Amazon or your local auto parts store. You say there doesn't seem to be any issues except the small delay when you turn off the motor. That seems to be a little bit of diesling. Probably you already fix the vavle, but you need to double check. Try erasing the code, if you haven't done so yet. If the light goes away thats a good sign otherwise do more testing and a re-scan.

      good luck.

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      Arthur Leite 10 months ago

      Hi Dan, I have an Mitsubishi Pajero/Montero Full Diesel V98W motor and almost thee weeks ago motor light turned on, I passed scan show us EGR fail, I oppened it an complete carbonized so I cleanned careffuly with Wd40 reset but motor light return and still ON, so my doubts are: 1- Is possible to drive car with this EGR Valve? Is it cause any damage? 2- Mitsubishi EGR is eletronic so how can I test it? 3- There are some sites that reccommend close/cover EGR open for definitely, is it possible and make sense?

      One sympton I identified is, when turno of the car by key there is a delay for motor shut of about 1 or 2 seconds, only turn of, no more issues...

      Thank you in advance.

    • Dan Ferrell profile image
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      Dan Ferrell 10 months ago

      Hi Mark,

      It'll be a good idea to check the EGR valve as well and have you tried to scan the computer? Any codes? Check for possible misfires. It seems more than one symptom due to maintenance.

      Good luck.

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      Mark Williams 10 months ago

      It seems Dan that I have high detonations when I go up hills on roads when I'm pressing on the gas pedal. My vehicle is a 1999 Chevy S10 truck, LS extend cab 4 cylinder 2 door and I have no EGR sensors that will trigger the EGR valve for my light to come. I did change the Fuel Filter, the tensioner and pulley, 3 TCC solenoids in the transmission since 1 did come up for the service engine light, and cleaned off the Idle Air Control Valve and passage. With high detonation while driving up hills , do you think my EGR valve is bad now or I should check my EGR valve out too? Also, new Air Filter, Oil Filter has been replaced but same sound still, plus sometimes the truck jerks after 1st gear, it can't be any solenoids in my Automatic transmission because they're new.

    • Dan Ferrell profile image
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      Dan Ferrell 10 months ago

      Hi Annie,

      sorry for the late response. You definitley need to have it check. That's not normal. Did they put too much oil in it? Did they put everything back the way they were supposed to? I hope that by now you've taken the car back and have it checked.

      Good luck.

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      Annie 11 months ago

      Hi Dan,

      I hope you can help. I have an Audi A4 tdi 2008 Cabriolet.

      Three weeks ago I stared getting some white smoke from my exhaust and an almost sweet smell with it. I took it to a garage where they had a good look. After a couple of weeks they have changed the EGR Cooler, rocker cover unit ( due to heavy sludge build up) 3 engine flushes, new engine oil filter, new air filter and replaced the engine oil.

      I have driven it home from work for the first time since having it back (30 miles) and noticed smoke from under the bonnet. I opened the bonnet and there was smoke coming out from around the oil cap....

      Is this normal after all of the work I have had done? I have just spent the best part of £900 on the repairs and I am now really worried about this new problem.

      Thank you in advance.

      Annie

    • Dan Ferrell profile image
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      Dan Ferrell 11 months ago

      Hi slkdnichols,

      it does sounds like an ignition issue. If they didn't replace anything from the ignition system maybe they left something unplug or not well connected (?). Did they tell you what the ignnition recall about? Did they replace something? Also, if they moved-replace something and system service is overdue, worn out ignition components will not handle power properly as per the new components.

      I'll start with this recommendations.

      Good luck

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      slkdnichols 11 months ago

      In addition to the comment above... I thought it might be the EGR valve that is having the issues... and it is just a coincidence that it happened at the same time as the ignition and timing belt were replaced. :)

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      slkdnichols 11 months ago

      I have a 2008 Dodge Charger with the 3.5L. I just had the timing belt replaced (I know I am late) and had recalls done on the same day. The recalls included the driver side airbag, FOBIK and ignition. Since that day, I have been having issues with the car. It is idling a little rough, I have lost hp and it doesn't shift down properly. In addition to that, I have had issues starting the car. I will turn the key all the way, let go of the key and the car starts after a second or two. Yesterday, I turned the key, I waited for the delay, the car started and then died... and then started again by itself without me touching anything!!! The dealership says that it isn't an ignition issue and the mechanic says that they didn't do anything when changing the timing belt! oh, one last thing, I was on my way home last week; the traction control and ESP/BAS lights both came on. They went back off after I let the car sit for a while at the house (turned off). HELP

    • Dan Ferrell profile image
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      Dan Ferrell 11 months ago

      Hi eldrun,

      have you done a compression check yet? If the white smoke is continuous you might have a blown gasket. You can do the compression check yourself with a special gauge, go to this link for the steps:

      https://axleaddict.com/redir/?redirectUrl=https%3A...

      Good luck

    • Dan Ferrell profile image
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      Dan Ferrell 11 months ago

      Hi Berttrim,

      It wouldn't hurt to take a look at the EGR passages. If you haven't done in the last couple of years, there might be some gunk stuck in there. The valve may open but buildup may prevent gases from flowing back in. Take a look and clean up as much as you can.

      Good luck.

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      eldrun 11 months ago

      hi

      I have got a jeep cherokee 2004 2.8 diesel. I am blowing white smoke through the exhaust.performance is affected and also fuel consumption is very high. please advise on my option on fixing the problem.

      it was initially thought that the turbo was was bad and burning out oil so had that replaced and was told after a few 100 mile it should stop but still have not. so question is is it my injectors or EGR valve or something else

      thanks

    • profile image

      Berttrim 11 months ago

      Hi,

      I wonder if someone could give me some information about a problem with my 1999 Nissan quest. This is virgin territory for me. A rhythmic bucking while standing at lights or in drive. Regular driving is better, but with the occasional bucking. When starting from cold it seems quite normal until warm 5 to 8 min. New alternator, not an ignition problem. Tested throttle body housing. I'm guessing EGR plugged, or Cat. No codes on dash. Before I dive headlong into this, does anyone have any other ideas. Thanks

    • Dan Ferrell profile image
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      Dan Ferrell 12 months ago

      Hi Dilly,

      Check for any DTCs from the computer first, you can go to autozone or your local auto parts store. Have them pulled any codes from the computer and start from there.

      Good luck.

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      Dilly 12 months ago

      I have a Mini Cooper s & when I'm in a traffic jam, stop start for about 20 mins the engine fan comes on, followed by the turbo light coming on then the engine coughing & spluttering & dying! Could this be the egr valve? It only happens when it gets hot & in this sort of traffic.

    • Dan Ferrell profile image
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      Dan Ferrell 12 months ago

      Hi Jim,

      First check what diagnostic trouble codes (DTCs) are stored in the computer. If you don't have a scanner go to an auto parts store, usually they'll retrieve the codes for your. When reading the codes, remember that the computer can only point you to the circuit it detected the "error" coming from; it won't tell you if an specific component went bad. You need to test the sensors, actuators, connectors, grounds, incoming power, etc on that particular circuit to find the fault.

      If a code points to the EGR, test the egr, the egr-sensor, any vacuum connected to it, electrical connectors, wires, etc.

      Good luck.

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      Jim 12 months ago

      Dan, I have a 93 F150 5.0 and so far have replaced throttle position sensor, EGR speed sensors and exhaust manifolds. Check engine light still comes on and after it comes on, I notice a decrease in power, especially on hills. Any suggestions?

    • Dan Ferrell profile image
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      Dan Ferrell 12 months ago

      Hi Terry,

      Make sure to check any EGR sensors, electrical connectors and wires. The computer is pointing you in the direction of the circuit not necessarily to the valve, although this could be your problem. Use the repair manual for your particular model to test the EGR valve and solenoid to pinpoint the problem.

      Good luck

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      Terry 12 months ago

      Hi there,I have a Toyota avensis 2.2 d4d car,my car will not start ,I had a crecorder in the car from the previous owner and I took it out ,it will not start now,I plugged the crecorder back into the car and still no luck,I have had a computer on it and it said egrvalve on computer,I have taken out the egr valve and cleaned it ,still nothing ,could it be ecu error and what do I do

    • Dan Ferrell profile image
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      Dan Ferrell 13 months ago

      Hi Danny

      Wonder what made you think it was the turbo. It's hard to tell without other potential clues. Have you thought of the drive belt? If you rev it up at idle, does it make the same noise? If so, you can use a piece of hose to listen to the pulleys, and idle pulley. A slipping belt whines when worn out or a pulley is out of alignment. If that check fails, stop by this forum:

      http://www.realworldautomotive.com/

      they get access to TBS just in case.

      Don't change components until you get a more accurate diagnostic.

      Good luck.

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      Denny 13 months ago

      Dan

      My girlfriend has a 2004 F250 with the 6.0. When she accselerates it makes a loud whining noise. We have replaced the turbo completely. We have replaced some other parts as well trying to trouble shoot it but still nothing. Could it be from the ERG or the AFRG? Wondering if you have any insite on what could be the issue.

    • Dan Ferrell profile image
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      Dan Ferrell 13 months ago

      Hi Pump

      It seems the ECU should be throwing a code, specially if the EGR has failed. If you're sure there's no problems with the vacuum hoses or EGR sensors' connectors and wires, take the car to a good shop and have diagnose the problem. Hopefully you'll be able to fix it on your own with the diagnostic at hand.

      Good luck.

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      Pumpturbinator 13 months ago

      Just bought My 04 MSM Mazdaspeed MIATA & it will not pass smog. The tester says EGR code reading incomplete. It doesn't give a code or store a code. Now I tried 3 or 4 times to drive the car in high gear then letting it slow down in high gear for over 20 seconds each time. I have driven the car 400 miles. The smog guy took it driving for a hour thinking he could get it to reset. I keep trying to reset the EGR but it doesn't work. Also pulled EGR and cleaned it. Then pulled intake to check it. This is a very clean car almost like new. 65000 miles. Very well taken care of by a old man in Thousand Oaks Ca. Everything is stock. The car runs good but has a rough idle. We have it set about 800-900 rpm. I also checked for a vacuum leek with a propane torch. All checked out good. New plugs, wires, oil change. Do you think Mazda can reprogram the ECU ? What do I try next before I spend big money at the dealer ? Or who do I ask ?

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      cherish 14 months ago

      Will a bad erg valve issue stop your car from starting but start after jumping

    • Dan Ferrell profile image
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      Dan Ferrell 15 months ago

      Hi Louis,

      You didn't mention if the shop checked any TSB (technical service bulletins) on that particular model. It seems to me there is a malfunction in the circuit.

      Since you already spent some money for a diagnostic without any results, why don't you go over to this forum:

      http://www.realworldautomotive.com/forums/

      These guys are pro and it's worthwhile signing up. Give them all the info on your car, the symptoms, tell them what they did in the shop. They'll even check for any TSB for you.

      Good luck.

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      Louis 15 months ago

      Hi Dan, In last couple of weeks my ford s max 2012 car battery went flat and i had a jump start more than 10times. When engine off, I noticed a 1.5minute beep and click sound from egr valve and it will stop for 30 sec and this will repeat around 30 min from engine stops. Also i can see the above egr valve open symptoms like odor of burned fuel. From saturday i got a malfunction symbol in the dash board and I have given the car to Taylor auto electricians and they said they did not find any drains and they replaced the battery and charged me £209 for diagnostics and battey replacement. I already mentioned egr sound to them, but they said this is quite normal. But still i can see the malfunction symbol in the dash board with computer message for malfunction and now the engine is running in limp mode. Yesterday I have disconnected the electrical connection to the egr valve and drove the car and i can see the engine yellow symbol in the dash board without any computer malfunction message and i got full engine power and limp mode removed, but the computer message comming back when reconnecting egr valve. I assumes that something happened in the electrical side of the egr valve. Could you please advise if i am wrong. Thanks..