Thread: Spun a bearing... again!

Just finished a rebuild on my SR20DET due to spinning a bearing on cylinder 2. The cause was oil starvation.

That said: 40 miles on the new build; I have rod knock and the oil pressure has crashed to 3 psi at idle. WTF?!?!? The entire bottom end is brand new. I replaced the oil pump. How is this possible? My friends and I are completely stumped. I've never seen nor heard of this happening to anyone before.

I think Nissan just hates me.

What can I do to prevent this from happening AGAIN?

take the block an have it hot tanked an cleaned at a shop an have the crank an rods checked also

Yeah, such a pain in the ass though. I had just picked this crank up. It had the works. Hopefully it isn't garbage now.

That was a gigantic waste of a grand. Depressing.

yea dude it always pays off in the end to take your time an dont cut ANY corners.. even if you dont mean to lol..

I had a problem with my engine at idle I had no oil pressure, I found it after 2 days of pulling everything apart, the oil pickup tube was not tightened to the oil pump causing it to suck air, might not help in your situation but goodluck

Hrm. I dunno, man. I had 25 Psi at idle and then for reasons unknown it has crashed to 3 Psi. I'm not sure if I should just pull the oil pans and take a look or if I should just throw the engine back on the stand and start over entirely. Just sucks to do this. I can't really afford to be doing this crap while I'm trying to finish college.

So you got a new crankshaft?
Or re-used the old one? If you re-used the old one, that's your problem right there.

Start over. Did you reuse your original rods from when you had rod knock before?

If so i can bet you the rod became out of round from the knock. Ive had that happen before. Put new bearings in and within 50 miles it spun again. It doesnt take much of a knock to pull those rods out of round enough to where the bearings just spin. Your bottom oil clearances on top and bottom may be good (which is where your supposed to check it btw) but the sides will be pulled in enough to take away clearance down to nothing. Ive checked this before. Plastigaued the bottom and top (good) did it on the side as close to the cap connection as possible and it was smashed down to nothing.

You should have invested in some Eagle rods. For the price you can get them for i wouldnt have risked it. Any motor that i get with knocking i dont even risk it and have the rods replaced.

It's a fresh machined crank (10 over, polished, balanced). The old crank is sitting in the garage. I replaced the rods with some OEM SR20DE rods. There was no way I was using the old ones. Rod 2 had the oil port essentially ground off. Also rebuilt with a full-set of Clevite bearings.

That's why I don't know what the heck it is. The only thing I can think of is maybe a journal somewhere is plugged.

Anyway it could be the turbo's fault? Both bearings spun on the same turbo. The first time it was within 4 miles after changing to this turbo (the bearings on the old turbo failed). This turbo runs very well though. After shut down it seemingly spins forever.

I could put some aftermarket rods in it; but I'm afraid this might happen again. Having a bearing spin with some nice rods in there would absolutely infuriate me.

Well either way, i would start over. Fresh crank, eagle rods, ACL race bearings and go from there. Should only cost you around $500 to redo with parts if you do the labor yourself. I know it sucks but ive been there done that.