How do you change the spark plugs and plug wires on a '99 Sunfire?

Answer 1

You don't say which engine you have, but the procedure on any of them is basically the same.

First of all, you want to make sure that you don't mix up the wires. For this reason, I usually do them one at a time.

Remove one of the plug wires from the plug by twisting and pulling gently on the rubber boot at the end of the wire. Move the wire aside. Now, using the proper sized plug socket (which has a protective rubber insert to protect the plug), remove the exposed plug. Note that plugs sometimes become a little rusted or corroded and are hard to loosen. You CAN strip the threads out of the head if you don't use caution. If you think that a plug is coming out entirely too hard, stop trying. Squirt some Liquid Wrench or WD-40 around the base of the plug and wait awhile. This usually will loosen it enough to get it out intact.

Once the plug is out, you're ready to replace it. Make sure your new plugs are properly gapped. (your parts house will tell you the gap and sometimes gap them for you) Smear a bit of clean motor oil on the threads of the new plug. This will help to prevent the rust/corrosion mentioned above. Gently begin to thread the new plug into the head. You might have to use your socket extension to hold the plug and to get it into the hole. Make DANGED sure you are not cross threading the plug! When it's threading in fairly easily, you can go ahead and tighten it with the socket. Get it real snug, but don't go crazy.

Next, follow the wire you took off that plug back to the coil pack, noting the routing and any hold downs. You might have to use Braille or The Force to do this, as the coil packs aren't always visible. Gently pull the plug wire off the coil pack. Now, plug the new wire onto the coil pack, reroute it to the plug and plug it snugly onto the plug. THAT'S ONE! This job is like using shampoo ... apply, rinse, repeat.

When you're done, start the car to be sure that you don't have a miss. If you do, it means that either you have a plug wire loose, or you've mixed up the wires. Turn off the car, check for these problems and adjust as necessary. Start the car again to be sure you've found the problem. If the car runs smoothly, you're good to go!

As always, having a Haynes or Chilton manual around is a good idea.

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