Rb20 Oil Consumption ? 1+litre In 300kms ? Highway Speed?

[robots]

Hmmm. My rb20 started to use oil. I've thought its the turbo before, so changed to rb25 turbo.

Now I went to another city and had my oil change before that. Oil level was a tad higher than H mark. Came there. Checked oil level next morning. Its on L mark ?Engine cold. People say it smokes on high rpm. Highway cruising was at around 140, no lower than 100. With 3-4 accelerations to 180.

Didn't check compression yet. So my question is: is this it ? The end ?))) Oil pressure is good according to greddy gauge. Never goes lower than 1,5bar at idle. Usually 2bar. 4bar is very easy as revs climb.

[2LV8ETR]

If there are leaks present, (which you should have noticed already) address that symptom first.

The most usual cause of engine oil consumption is worn valve guides, usually the exhaust guides or worn rings.

Run the engine for several minutes at idle. Turn the engine off and let it sit for about 15 minutes. Restart the engine and immediately increase the engine speed while observing the exhaust. If a heavy billow of bluish smoke is exhausted then disappears and the exhaust remains relatively clean, the most likely cause is excessive valve guide wear. In this case, the valve guides or valve guide seals require service.

If the above test only produces mild smoke and the smoke remains at the same level during all operating conditions, the piston rings will have to be compression tested. Use both the dry and wet methods with WOT for a good evaluation.

[The Dan]

Keep in mind that for it to use 1L in 300km it would have to be pissing smoke out at idle. That's a lot of oil to be using.

The smoke at high rpm is not likely to be oil smoke but people will always tell you about it. I'm not saying it definitely isn't but you should do a compression and leak down test as suggested above to ensure the rings are sealing correctly.

Are you checking the oil on completely level ground? If you check it on an angle, it will give you a false reading. Where are you checking the oil level?

[robots]

Ok. Compression tested today haha. 9.5 in cylinder 6. Other 5 - 10. Motor is in a pretty good nik.

Hmmm. after some observation. The hose from cam cover to pcv valve was blocked. So pcv valve was blocked all the time. Changed the hose didn't change anything. Still smokes. So my other intelligent guess is turbo is farked. Any more ideas ?

If I give it rev at idle. It only smokes after near up to redline rev. And it smokes when the revs drop to idle. Also smokes like crazy when accelerating under load. Around 3-4k rpm.

And no, I don't have an oil catch tank installed yet.

What do you guys think ?

[BANGN]

good compression will not tell you if an engine isnt burning oil, it just tells you that you have good compression. Pull the plugs and have a look at the colour

if one way valve on the intake manifold is blocked the turbo will just circulate the oil into the combustion chamber, if thats the case for the amount of oil you are using the intercooler will be full of oil i rekn

Edited June 28, 2009 by BANGN

[robots]

I will be observing my oil levels during next few weeks. I don't drive often. If the one way valve fixed the issue - I'm all ok. And oil burning now is the oil left in the intercooler/pipings. I reckon. If not I will need to dig further. Any more ideas on diagnosing the problem ?

Edited July 1, 2009 by robots

[VB-]

leak down test results?

[tridentt150v]

If your overfuelling, you will wash the oil sheen off the bore. Not saying thats the problem, but 1 litre in 300km is the sort of effect it would have.

[robots]

hmmm. Haven't got around making a leak down tester. So no leak down test results yet. Hmmm. I would see 11afrs at WOT. And usuall 14.7-15 at idle.

I wouldn't say I'm overfuelling.