I've got what seems to be a lower engine knock in my 97 3800 V6. I've had it on the road for two days and this is just devastating for me. My old vehicle is junked so I've got to fix this as soon as possible. The car has 241k on it but was supposedly well maintained.
Being 19 and having my first Camaro I jammed it around the day before a bit with a few burnouts but nothing too major. The second day was just city cruising and the knocking developed. I drove it home and the knocking slowly got louder, but the next morning it had quieted down. It doesn't seem to knock when it's idling but when I give it gas the knocking is very evident, the same during start-up. Though when driving the knock seems to stop completly at around 50km/h.
I was wondering if there could be a common cause for this. I know it's sort of vauge but any help would be greatly appreciated.

 

Is the car an automatic or a stick?

 

It's an auto.

 

You could have a cracked flex plate (AKA Fly wheel). I have seen a few cars that people though had rod knocks that where cracked flew plates.

But most likely your RPMs got a little high during one of those burn outs. With those many miles these 3800 (or any other motor) are not very forgiving. The noise level changing is very comon with a motor tearing itself apart. Parts that start grinding get very hot and they expand. That expantion makes more noise in some cases. The only thing that will let it cool is not running it. So the next day it sounds better. Until it get all warmed up again.