In the spirit of helping improve your document for others who have
yet to experience the joy of a bad coilpack, I'd like to provide the
1.) My car idled rough for about a year (especially on rainy days)
before the check engine light came on, and when it did, the car
stalled, and I was stuck on a highway in a snowstorm. When I was able
to get it started again, the arcing was very noticeable. To be fair,
I've read elsewhere that these coil packs also go bad due to
corrosion on the inside, so I don't know if my rough idling was from
the cracks in the surface or internal corrosion, but I think if it
was corrosion, it would not have been dependent on humidity/rain.
Maybe saying the check engine light WILL come on is a bit strong.
Anyone experiencing rough idling in wet/humid weather should probably
check the coilpack, regardless of the check engine light, IMHO.
2.) On my 97' GTI VR6, I was able to remove the coilpack with out
removing the plastic engine shroud. It didn't even get in the way.
3.) You should point out that the posts on the coilpack are numbered
1-6 to indicate what cylinder they should go to. The spark plug wires
should also be numbered, to make it easy to reconnect the wires
correctly. I know this is obvious to anyone who has ever looked under
the hood, but maybe someone will read this who never has looked under
4.) On my car the check engine light went out 24 hours after the last
fault occured, regardless of how many times I stop and start the
engine. I had several opportunities to observe this before I coudl
replace my coilpack :) I don't know if this behavior is the same for
other models/years, and is based on ym own experience, not anything
97 GTI VR6