Change Spark Plugs
In most cars, changing the spark plugs is simple and fast. Be sure to follow these direction in order, however, because a mix-up can be very confusing to fix. You'll see what I'm talking about in a minute.
Step 1. Locate Your Spark Plugs
Locate the spark plugs. If you follow those thick, rubbery wires under the hood, you'll find the spark plugs (one at the end of each wire.) If you have a 4-cylinder engine, your four spark plugs will be at the top of the engine in a row in front of you. If you have a V8, you'll have to reach down on both sides of the engine to get them out, four on the left and four on the right. If you have a 6-cylinder engine, they could go either way, but if you follow the wires you'll find the plugs.
Step 2. Spark Plug Wire Removal
You're about to reach for those spark plug wires and pull them all out at once, aren't you? Don't do it! Your spark plugs fire in a specific order, and it's a heck of a lot easier to replace them one at a time without getting them mixed up.
Starting at the end of the row, pull the wire off the end of the spark plug by grasping it as close to the engine as possible then pulling. You might have to give it a little wiggle to get it off. If you have a 4-cylinder engine with the plug wires going into the top, your plugs might be at the bottom of a hole (if you have a dual over head cam top end configuration). If this is the case, just pull straight up and you'll pull a long rubber boot out of the hole.
Step 3. Removing the Spark Plug
Now that you have one plug wire off, put your spark plug socket and the extension on your ratchet. If you look inside the spark plug socket, you should see some black foam or rubber on the inside end. This is important, because it holds onto the spark plug while you maneuver it in and out of the engine.
If for some reason your socket doesn't have the gripper in there, you can improvise. Cut off a half inch or less of electrical or masking tape and stick it onto the inside of the clean socket. This will make the socket grip a little more tightly on the spark plug so you can hold onto it.
With your ratchet wrench set to loosen (that's counter-clockwise) slide it over the end of the plug, being sure to push it on as far as it will go. Now remove the old plug.
Step 4. In With the New Plug
Put the plug-wire end of the plug in the socket and, holding just the extension, push it all the way in. Now carefully guide the spark plug into the hole. Try not to ram it in or bang it on anything because this can screw up the gap or damage the plug. With it sitting in the hole, begin to screw the new plug in by hand. Starting them off by hand instead of using the wrench will keep you from accidentally cross-threading one of the plugs. Screw it in by hand until it stops, then put the wrench on the end and tighten it snugly. If you have a torque wrench, you can torque it to spec, but if you don't, just make it tight without overdoing it. The metal in there is soft and can be damaged by overtightening. If you are pulling hard enough to make a sound come out of your mouth, like a grunt, you're overdoing it.
