Engine drinking oi! help!!

[The_Eric]

Originally Posted By: KitaCam
Originally Posted By: RFAF
Hello guys,

i have this problem with my engine. it consume A LOT of oil when it is high rev. about 1 quarts for every 10 mins of high rev around 6000rpm!!!
Running out of idea. Anybody can help?


Yes....stop running your engine at a constant 6k rpm....YOU are ruining the engine....it likely wasn't built to operate that way.
...next...
Take the engine apart and have it rebuilt by a racing engine specialists who MIGHT be able to install crankshafts, camshafts, valves, guides and even pistons if available and expressly made to operate under those conditions...
6 grand on an LS7? Not a big deal.

 

[05LGTLtd]

Oil can only go one of three places when it's lost.

1) Out the exhaust. You say compression is fine.

2) Into the coolant. With a gallon of oil reported missing, I'd think you be seeing the overflow full of oil. Possible your burning coolant at the exact rate your leaking oil, but I doubt it. Drain the coolant to check.

3) Ground. I really think it would be hard to miss a gallon of oil leaking out of an engine. If Trav is right, there should be a decent oil slick in that location. If you have managed to blow out the main rear seal, it could all be in the bell housing, but I think you would have seen some on the ground. If there is a rubber plug, pull it and see.

If this was a Forced induction engine, I'd be betting on a cracked piston/failed ring.

 

[Doog]

Pull the valve covers off and see what you have.

 

[ironman_gq]

Oily bores will give a false high compression reading, sounds like your rings have lost tension and are letting oil by, the oil on the cylinder walls is sealing up the rings when you do a compression test.

At a minimum I'd say your oil control rings are shot or they used low tension rings, maybe they put the rings in upside down.

 

[RFAF]

Hi guys,

Thanks for all your comment and ideas.

1. This is LS7, modified by a racing engine company from US. cam, con rod, pistons etc has been upgraded for high power operation. Sorry that i cannot disclose more about our supplier without their consensus.
2. This is V8 engine. we see oil stain in all cylinders. That's why we do not think is piston oil rings, valve guide & seals. (unlikely that this problem happen to all 8 cylinders right?)
3. We checked coolant. no oil sign =(
4. visually check the engine. no external leak.

My question:
We have people pointing out that oil simply evaporated if too hot. previously we are running the engine around 300F. Now the cooling is better so it is at 250. In both case, oil is still missing. Is it common for the engine oil temp to be around 250F during high power? How about 300F?

Any more ideas? Please keep them coming =)
Appreciate all your comments. thank you!

 

[05LGTLtd]

Were you seeing oil loss previously, if so how much? Your OP makes it sound like this problem came on all the sudden.

 

[05LGTLtd]

So did you find where the oil loss is comming from?

 

[TFB1]

Generally oil can only enter cylinders by bypassing the rings, through valve stem seals or PCV system... Over heated oil is usually evaporated out of the vent(does it have a catch can?) and/or drawn into intake by PCV system... If oil is in cylinders but not intake, the engine likely has ring or valve stem seal issues...