My Sunbird, in it's dying days, was making a thunking noise that I could feel in the pedal, and it varied with speed...if I went high RPMs or hard brake, it would stop...it was believed to be my transmission, and killed the Sunbird within 36 hours of the symptoms appearing...

Now, my 97 Cavy LS vert 2.2 auto is doing the same thing.

What the hell can/should I do?!

Okay, problem fixed....the aftermarket lug nuts I had gotten had loosened themselves in the 1 day since I put them on...needless to say, those will be returned to the place I bought them from ASAP...

I'm confused how did lug nuts make your car quit?

the losening of the lug nuts made the car shake and clunk and he thought it could of been the tranny as in his 89 sunbird....but it was just crap aftermarket lugs @!#$ w/ him

LOL yeah, it was aftermarket lug nuts on the Cav....still had the factory nuts on the Sunbird...but when taking off the lug nut caps, several lug nuts came off with them...I mighta given up on the Sunbird for a minor problem that, in retrospect, could have been fixed in a matter of minutes, but I didnt know, and I feel the better for it...so much was wrong with the Sunbird, and I was sick of it, and had every intention of getting rid of it this year....though I expected to sell it to a person for a good price, Im still happy with the turn of events...