I have a '99 Lumina base sedan with the 3100, and have a question about a noise it makes. Hopefully someone has heard it before or knows what it may be, but here goes:
There is this sharp pinging noise that comes from the upper manifold in the front ('left side") of the engine. Also, when I use my old-school mechanic steth to listen to it, you can feel the pings go through it. You can also "feel" the noise through the left engine mount (seems like it supports the manifold's heat shield somehow).
Anyway, I've only heard two other cars do this and they were both Chevys as well (Tahoe and TrailBlazer, both newer models). Car seems to do it while it's warming up, while it's idleing (unless it idles for a long time, then it stops) and when it's shut off.
I brought it to an ASE mechanic who also does exhaust work but he just listened to it and thought it was normal. He said the car isn't running to hot or anything, and it isn't a mechanical problem, so it's nothing much to worry about.
I'm not worried about it, but do any of you have a remote clue what does this?
p.s. if you would like an MP3 sound clip (I know it won't help that much since you can't see the car in person, but it's something) let me know.
Thanks