I floored the car in first for the first time today and got a rather nasty knocking sound from about 3.5krpm all the way up to redline. Seems like if I go WOT from the get go the knocking starts in sooner than if I ease into it more.

When I took the car on a test drive I did the same thing, floored it coming onto the freeway but I was in second I believe. I got the same nasty sound. The seller rode with me and said I just hit the rev limiter. I wasn't watching the tach and I wasn't used to how fast the car wound up so I thought I'd gone past 5k rpm.

Did GM set the rev limiter around 4k for some reason? Seems a bit low. I haven't had any issues with any of the higher gears so I'm kinda confused.

Oh, also. I put the car in neutral, reved her all the way up to 5k without a glitch. I'm thinking when the car is under load it switches over to a lower rev limiter?

 

ttt

 

Its not the rev limiter...should be set at 5800. It could be a broken tranny mount if it sounds like its right under you.

 

Did the car loose power?? Mine did that and it ended up to be a spun bearing. I know you didnt wanna hear that. I broke 2 trans mounts and doesnt sound like thats the problem. Does it keep knocking?

 

Well I had my dad ride with me this afternoon to check it out. He was a mechanic for 15 years so he has some experience under his belt. Anyways, he said it sounded like the rear end twisting. I don't know the name for it but there's a support that runs from the tranny area to the pumpkin, acts as a stailizer, keeps it from wrapping up. He said it sounded like either a bolt was missing or a bushing or two had gone bad.

Basically I eased into the higher rpm range and then kinda stabbed the throttle, which gave the rear end a good dose of torque. That's why it happened more in first gear, because first gear is more torquey. Anyways, it's not for sure but he seems to be pretty confident that's what it is.

Those who replied I do appreciate you taking the time, I'll let you guys know when I found out for sure.