Hey guys, I just wanted to share my info so that maybe others who are having similar knocking noises can compare notes

I bought a 97 coupe in Sept, knowing that it had a bottom end knock. The guy told me he ran it low on oil, it started knocking, and then he just parked it for a year. The rest of the car was in great shape and the price was right, so I took it home. I didn't get time to play with it until this weekend. The only thing I did before storing the car was cut the oil filter open, and surprisingly nothing looked awry. No shavings, no metallic sheen, nada.

Before I tore it down, I took a quick video of the noise -

http://www.youtube.com/watch?v=gRSrUQudaP0

I pulled the engine out from the bottom. I made a thread about that earlier, check it out here if you are interested. I then pulled the rest of the drivetrain out, I also needed the trans rebuilt as 6th gear was damaged.

Once I got the engine out, I pulled off the heads first and the pistons looked pretty normal.





So I put it on the engine stand and flipped it over. I pulled off a few rod caps and when I got to the #6 cylinder, I found the culprit: a spun bearing. It wore the crank journal down pretty good. The only pieces of bearing I found in the engine were two thin shards; one trapped in the oil pickup screen, the other hiding in the back corner of the batwing oil pan.







I have an 8k mile LS1 longblock that I will be reinstalling into the car, I began transferring components last night. I'm waiting on a few random items (gaskets, etc) to come in this week, and hope to get it put back together next weekend.

 

Nice work. Are you doing any mods to the new motor??

 

Yeah, seems like a lot of work to replace with a stocker.

 

I never realized that the bearing would eventually come completely out of the journal.

 

I'v heard that sound a few too many times

 

To be fair, I enjoy it, so it's not much of a chore to pull engines. I plan to sell the car, so I am pretty much replacing what needs to be fixed with new OEM stuff.

 

Glad you enjoy doing that stuff, wish I had the knowledge and the tools to try and do my own work.. One day maybe. Good luck with everyting!

 

Well done on the find. Did you pull the engine from top or bottom?

 

The engine was pulled from the bottom, per the first post.

I'm surprised that the oil pressure was as high as it was without the bearing shell.

 

I'm sorry that I was confusing in the pics - the bearing was still in the journal, just spun. I wasn't thinking when I snapped the pics of the rods with one bearing in and one bearing out, sorry!!

Bottom! I wrote a how to during this - http://keliente.com/c5engine.htm

 

nice write up. LS1's are known for this. I know of at least 4 or 5 that has spun one. Including mine.

 

^^^ I didn't realise it was that common? I've heard hit or miss but not common. I sure hope mine doesn't or i'm gonna have to build a 408

 

mine along with my buddies has the same problem, is there a way of finding the culprit and replacing it WITHOUT pulling the engine. thanks!