Tom Lohr is an avid home improvement enthusiast. He prefers to spend the money he saves on new tools and gardening supplies.
Your CRV Loves You...Love It Back
Spark plugs are the devices that provide the source of ignition for the fuel/air mixture that is injected into each cylinder of your car's motor. The spark it provides causes the mixture to explode, driving the piston down, which turns the crankshaft which turns your wheels via the axles. Most engines have one spark plug per cylinder, so if your car has a four-cylinder motor, it has four spark plugs.
Spark plugs wear out. In the not-so-distant past, you needed to change out the plugs every 30,000 miles or so. Today, the majority of autos have long-life spark plugs that last anywhere from 70,000 to 100,000 miles. Your car's owner's manual will tell you how often they need to be replaced. Be wary of any component, including your plugs, that are listed as “lifetime” parts. For practical purposes, you should consider a vehicle's “lifetime” as 100,000 miles. The problem is, the average car on the road today is nearly 12 years old. With the average miles driven per year just over 14,000, you can easily see that there are many cars out there that have clocked well over 100,000 miles. When you reach that milestone in your vehicle's life, it is time to start replacing parts that are nearing the end of their expected usefulness.
To function, spark plugs need a hefty dose of electricity. The charge is delivered via ignition coils that connect to the top of the spark plug. They are long cylindrical plastic devices that have a coil inside. On the top of your engine block, there are four holes. At the bottom of each of those holes is a threaded hole that the spark plugs screw into. The rest of the room in those long holes is taken up by the ignition coil. The coils, like the spark plugs, have a limited lifespan. If you plan on replacing long-life spark plugs, you should replace the coils as well.
Why You Should Replace Spark Plugs and Ignition Coils Yourself
You could easily take it to a mechanic. If money was no object, that is what I would do. Unfortunately, replacing the plugs and coils at a car shop can easily cost you $500. That is not a small amount of money. The good news is you can change your own spark plugs and coils on your CRV for less than $200 and about an hour of your time. The $300 you save will fill your gas tank many times. And with new plugs and coils, your CRV should get better gas mileage, meaning you won't have to fill it as often. An extra bonus is you will probably notice a slight increase in engine performance.
Changing out the spark plugs and ignition coils is a money-saving DIY mechanic project that is not only simple, but also requires few tools. If you are not afraid to get your hands a little dirty, you can save a bundle. Of the two (plugs and coils), the ignition coils are the most expensive. You can get them at the dealership (not recommended), at an auto parts store (better than the dealership but not ideal) or order your own CRV ignition coils and get the best deal. Here's how to complete the project:
Tools and Parts Required
- 4 new spark plugs
- 4 new ignition coils
- socket ratchet
- 10 mm socket
- socket extension (one at least 8 inches long)
- spark plug gap tool
- 3/8 inch spark plug socket
- very small flathead screwdriver
You can only perform this project if your CRV's engine has cooled down. It takes a recently running engine quite a while to reach a temperature that is safe to perform maintenance on it. Working on a hot engine will have you reaching for the burn cream. If the engine is too hot to touch, it is too hot to work on. Give it at least an hour to cool down before attempting any maintenance.
You should also always set your parking brake when working on your vehicle. After you have gathered your tools and parts and set the brake, it is time to pop the hood. The hood release latch is a little difficult to locate if you have never used it. You have undoubtedly used the gas tank door release when refueling, the hood release latch is just to the right of it, set back a few inches.
Put your fingers on the gas tank latch and then slide your fingers to the right and back and you will feel it. Once your hood is opened and propped up with the rod that swivels from the front of your engine compartment to the corresponding hole on the underside of the hood, it's time to get down to business.
Remove Spark Plug Cover
Protecting your precious spark plug ignition coils from road grime is a black plastic cover. It sits directly on top of the motor, just behind the oil dipstick. The cover is held on by four bolts.
Use the ratchet and 10 mm socket to remove them. The screws are specialty screws and not easy to replace if lost. Keep track of where you put them.
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Disconnect Ignition Coil Connectors
After the cover is removed, you will see the tops of the four black ignition coils. There is an electrical connector attached to each.
To remove the connectors, use the small screwdriver (or something similar) and lift up on the small tab in the center of the connector.
Lifting up the tab down with one hand, use the other to squeeze both sides of the connector and pull back to remove it. It should come off easily. Don't yank on it.
Once all four connectors are removed, they are grouped and held together, it is easier to move the connectors back and out of the way for easier access.
Remove the Ignition Coils
Each of the coils is secured with one bolt.
Remove each bolt using the ratchet and 10 mm socket.
After removing the bolts, pull out each coil by pulling straight up. They fit snug and are connected to the top of the spark plugs so it may take some effort.
Remove Spark Plugs
After removing the ignition coils, if you look down into the hole it came out of you can see the top of the spark plug. It is pretty far down. Getting them out will require the use of the spark plug socket and socket extension. Spark plug sockets are deep to allow the upper body of the spark plug to fit into it. Additionally, there is a rubber gasket inside of the socket that grabs onto the spark plug so you can lift it out.
- Attach one end of the socket extension to the ratchet, and the spark plug socket to the other end.
- Ease the spark plug socket into the hole until your feel it hit the top of the spark plug.
- Manipulate the ratchet until you feel the socket properly gripped to the spark plug.
- Set the ratchet to turn counter-clockwise and begin unscrewing the spark plug. The first half turn may take a good bit of effort until the plug breaks free.
- Once you are certain it is completely unscrewed, gently lift the socket out. The upper part of the spark plug will be stuck inside of the socket.
- Once clear of the engine, pull the old plug out of the socket and discard it.
Check the Gap on the New Spark Plugs
One adjustment that is important to get the correct size spark from the plug for peak engine performance is the spark plug gap. At the bottom of the plug, there is a tiny electrode. Emanating from the body of the spark plug is a flat piece of metal that protrudes slightly down and then makes a 90-degree turn and ends up directly under the electrode. The distance between that piece of metal and the electrode is called the gap. The gap is where the tiny lightning bolt type spark occurs. The distance of the gap is important. Most spark plugs come pre-gapped, meaning you are not supposed to worry about how big or small the gap is. NEVER trust pre-gapped plugs. Always check the gap yourself.
To do so, you use the coin-shaped gap tool. Along the edge of the gap tool is a lip that starts out thin and then ramps up in thickness as it circles around the edge of the gap tool.
Insert the lip of the gap tool into the gap on the spark plug.
Slowly turn it until the increasing lip fits snuggly into the gap on the plug. Directly above the gap is a number stamped onto the gap tool; that is the size of the spark plug gap.
Check the owner's manual to ensure it matches what you have measured (normally the gap is .044 inches). If it needs to be bigger or smaller, gently bend the lower part of the gap until it is the correct size.
Insert New Spark Plugs
Stick the end of the new spark plug opposite the gap into the spark plug socket. The rubber gasket inside will hold it in place.
Connect the socket to the socket extender.
Slowly lower the spark plug into the hole, and ensure that you are not tilting it as it is lowered. It is important that the threaded end of the spark plug sits squarely on the hole it screws into.
Using your fingers, turn the socket extender clockwise carefully to get the spark plug started. If there is much resistance, reset the plug on top of the threaded hole it screws into. You do not want to cross thread the spark plug.
Once you can no longer screw it in with your fingers, attach the ratchet and turn the socket clockwise until it is snug.
Give it one last medium tug and remove the socket from the hole.
Insert New Ignition Coils
The bottom of the ignition coil snaps onto the top of the spark plug. Before inserting the coil into the hole, ensure that it lines up with the hole that the coil retaining screw fits into.
Lower the coil into the hole until it meets the spark plug.
Push downward until you feel it pop into place. If needed, you can turn it slightly to adjust its position so that the hole on top of the ignition coil is aligned with the hole that the coil retaining screw fits into.
Use the ratchet and 10 mm socket to insert the coil retainment screws.
Re-Attach the Ignition Coil Connector
The electrical connector for the coil snaps into place when you push it directly in. You do not have to manipulate the center tab on the connector to re-attach it.
Replace the Cover
Once you have replaced all four spark plugs and ignition coils. Replace the cover by sitting it on top of the coils and attaching it using the four specialty screws.
Test Your Work
Leaving the hood open, start your CRV. It should sound normal. If not, immediately turn it off and review your work. Remove and replace each plug again if necessary. While it is possible you received a faulty new plug or coil, it is unlikely. If you followed the procedure, your engine should purr.
Tell the Local Shop to Shove It
There are numerous repairs and adjustments to your vehicle that are best left to trained mechanics. But many you can do yourself. No car repair or maintenance procedure is cheap, all of them take a nasty chunk out of your budget. Do the maintenance that is simple yourself and save the money for other expenses. Changing your spark plugs is one of the simplest DIY vehicle projects you can tackle. Once you have changed your own plugs and coils, take a step back, admire your work and then ask yourself what other car maintenance you can do yourself. If you successfully changed your plugs, you have the skills for most other regularly scheduled maintenance items. You are now officially a grease monkey.