Hello All:
My '97 GM (190k miles) is cackling so badly in hot weather I'm almost afraid to drive it- I've switched to plus grade gas and even that isn't helping. If this was an old car you would just set the timing back a few degrees, but since the timing isn't adjustable, what do you do? Do I have to take the heads off and have the deposits it undoubtedly has scraped out? It runs like a top but I'm afraid I'm going to burn up valves or damage the pistons going like this. CN
have you checked the OBD-II for any codes? This may help diagnose the problem.
I suspect you have one or more of several problems. First, clean the MAF sensor. The throttle body and IAC also probably need cleaning. This can be done when you clean the EGR ports if you have never done this. Make sure the PVC system tubing is open and the tubing is in good condition. They tend to crack near the throttle body and become plugged with carbon and sludge. This is almost never a timing issued on these engines.
Lungnut
I'll take a look, thanks for the suggestions.
CN
You can pick up the T-20 tamper proof torx bit at most auto parts stores. The whole operation takes only about 15 minutes and is easy. Just handle the MAF with care.
The improvement is usually amazing.
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