Light Engine knock

[gmtech99]

Ok guys, got a question for you..I have an 02 and it had a int light knocking noise that I thought was coming from the loose water pump that I but after replacing that the noise is still there..sounds like its coming from underneath by the torque converter or that area of the oil pan....don't think its coming from balancer....are the flexplates known to crack on these? only does it at idle..as soon as you come off idle the noise is gone....any help would be appreciated

[Fivefingerdeathpunch]

They do crack but not very often. They tend to be louder than just a faint knock noise though, often the same pitch as a spun rod bearing.

I'd maybe even try some trans fluid in the oil to see if it clears anything up that may be from a lifter making noise. Or drive it and see if the noise starts getting worse.

[b4black]

They do crack often. They start out faint and get worse. Pull the inspection cover for the torque converter off. It's just two 10 mm bolts.

This should help.
http://www.grandprixforums.net/threa...g-sound-06gpgt

[gmtech99]

I did pull the inspection cover and looked but didnt see anything but it is hard to see, but thanks for the link..the more reading I did it sure sounds like the flexplate guess I'll just have to take a closer look...maybe seperate the t/c from it and try running it and see if noise is gone.

[gmtech99]

The noise should go away if I seperate the t/c from the flexplate correct?

[b4black]

Mine didn't. But without the TC spinning, I know the issue is not in the trans.

[gmtech99]

Its got me worried. .only does it at idle..no noise after that

[b4black]

That's pretty much what happened when my first flex plate went. Knocking at idle and a bad "buzz" sound when decelerating. I could see the cracks in the flexplate between the three windows. It was cracked all the way around once I got it removed.

Now I'm getting the same rattling at idle only. I can't see any cracks, but I'm 90% sure it's a flex plate again.

[gmtech99]

Yup..crawled under there today and looked a lil closer and saw a crack...flexplate it is