i started my motor after rebuild, reved it to 4.5k and boom!!!oil everywhere.
i checked all fittings , hoses for oil cooler everything seems ok, i pretty sure its rear main seal... it was oil and i should have replaced it. can this seal cuz instant oil loss? i lost about 3 qt. in seconds.

 

it was old*

 

well, my rear main seal is leaking, but it's nowhere NEAR that sort of oil loss. The only time i've experienced that sort of thing is when my oil cooler lines blew.

 

i dont see where else it could come out of

 

you revved your fresh rebuild to 4.5k straight away?

 

Oooh can I post something useless making fun of someone who doesn't know any better too?

Be helpful. Yeah, you're supposed to keep it under 4000 for the first 1000 miles or so of your rebuild, but if it blew at 4500, it would have probably blown at 4000.

I wouldn't think a rear main seal would cause that. Besides, even if it was old, you should be able to tell by looking at it if it's good or not. Yeah, maybe it's a good idea to replace it, but not all of us are rich FC Tycoons. :P If there weren't any obvious scratches or signs of dryrot or whatever, it's probably fine. Most rear main seals lose oil like a qt/month or so. Unless it completely left the building which is hard to believe.

Oil cooler lines will dump oil that fast though. Or loose oil pan bolts/drain plug. Or maybe a oil filter with a double gasket? You'd probably see that one pretty quick though. On a rebuild, it should be pretty easy to see where the oil is coming from though.