Does a spun or warped bearing have a rhythm to the noise or is it inconsistent? I'm beginning to think it might just be loose torque converter bolts, as I have seen some threads where they thought it was the same thing, and turned out to just be loose bolts.

 

If it did **** a bearing up, would an SES light come on?

 

I spun a #6 rod bearing "stacked it" trust me if you spun a bearing you would definatly know it.. it sounds like the engine is coming apart.

 

ttttt

 

Jason's right, a spun bearing will sound like gunfire in the engine bay. I do not think it will trigger the SES light, but it might induce a KR ( knock retard ) signal.
I think you posted earlier that there was a drop in oil pressure? If so this is another good indicator of a bearing and/or oil pump problem.

 

there isnt a drop in oil pressure, just a fluctuation. The oil pressure is still very strong, which is odd if it has anything to do with a bearing. Any ideas?

 

If the oil pressure is still good then the TC bolts are definitely something to check. I also have heard in this forum about loose bolts causing a similar sould/issue.
Let us know how things turn out!

 

if its your converter bolts backing out it sounds like a machine gun or sticking a object into a fast moving fan..

mine backed out after 5 thousand miles i coated them with red loctite and they seemed to hold

 

didnt stacked mine but moved it quite a bit.ran mine low on oil while racing.lesson learned on that one.

 

You might've just crushed the bearing, but only enough to drop a couple PSI of oil pressure. This exact same thing happened to my friend Ernie's 18* SBC motor. He made a pass on his big shot of dope (450) and popped a headgasket at about the 60' mark. He changed the headgasket and went back to the track, but noticed that he had 15 less PSI of oil pressure. His next pass would be his last for a while. Not only did he finish off that rod bearing, but he burned a hole in a piston.

A spun rod-bearing might not sound that bad if it isn't totally destroyed. There might be a small ticking. If your convert bolts had sheared themselves, or you had cracked the flexplate, wouldn't the noise get louder when you put the car into Drive or Reverse?

If it turns out to be a rod bearing, make sure your next set at coated bearings. An extra 100 bucks might turn out to save you from having to re-build a motor.

 

thanks a lot for the replies! if anyone else has ideas or stories, please feel free to add.

 

I hade loose converter bolts, I thought I spunn a bearing or something. The noise was a constant, thunp, thump, thump so I got ready to remove the engine and when I got to the converter and found I had loose bolts, I stoped tightend everything and the thumping was gone. One big clue that I figured out later was the thumping came and went, if it was a spun bearing it would be a constant thumping.
A bad or scored crank journal would also thump. So if you have major changes in your oil pressure this could score a journal or bearing. Wich, would lead to a spun bearing or a snaped crank. Change your oil, use a clean receptical sift the oil with a coffe filter. Cut your oil filter remove the element inside, woe look for shinny stuff and bits of steel. But, don't wait too long.

 

I haven't been driving it at all. It's pretty damn constant, but it is a very inconsistent sound with no real rhythm. I'll have my friends check it out today (my car is 500 miles away).

 

good luck.hope you find the cause and fix soon.

 

You may not see any loss of oil pressure with a spun bearing.I didnt.
One sure fire way to tell if its a bearing is to pull spark plug wires while its running and see if it stops. Pull the plug wires one at a time and put them back on(just like checking for a miss)when the knocking goes away you found your bearing.If the sound dosent go away look elsewhere.

 

What?

 

Try it next time. Ive done it many times.It sounds stupid but it works. Only works for rod bearings.

 

Yes, he is right... I know that method, but unfortunately it is in Dallas and I'm in NM. Thanks though!

 

Ah, yes it makes sense to me now. Thank's for the tip. I'll file that away in memory.
Dale