What's this in my oil pan?

[tedex]

Can anyone tell me what this is (not the penny)?

Here's the story: I had a knocking noise in my red-top sr20 that sounded like it was coming from the lower engine. I assumed it was a spun bearing. I started a tear-down to confirm this, and when I pulled the oil pan I found this in there. It's aluminum, has somewhat of a taper, it's pretty worn but I assume (maybe incorrectly) that it was a full circle originally. I don't know if this was the source of the noise or not and I'm still in the process of checking the bearings, but there wasn't any metal or shavings in the oil (except this). Anyone have any idea?

[allenms240]

Hmm. I had a small piece on my pan, it turned out to be a nick off one of the main caps. But that looks too round-ish to be that.

[Lobo240sx]

That same piece happened to somebody's SR20 that is on this board, except theirs was sitting on top of the piston.. I'd tear it down and check all your bearings. Looks like part of a washer. If you find out where it came from, let us know.

[tedex]

You know, I know I saw something just like this at one point on this forum, but I can't find it any more.
I've strained the oil through a paint strainer and, other than some paint from the oil pan, there was nothing in the oil. I thought it could be part of a shim from the head, but everything appears to be in order up there. One possibility I was thinking was something from the oil pump. I will tear it down further to find out for sure and keep the forum updated. I hate when people don't resolve their own threads. If anyone has more information, I'd love to hear!

[wa-chiss]

You said it's tapered? Check your valve springs. ALL of them, top and bottom. That looks like the end of a coil to me.

[tedex]

I would think that, except it's non-ferrous (aluminum I'm assuming). I also think it's circumference is too small. Assuming a complete circle, it comes out to about the size of a dime. I'll be tearing into it a bit more tonight and keep you guys updated. Thanks for all the replies.