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Blue Smoke On Boost

moonie

By moonie,
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moonie Rookie

moonie

Posted
Posted

A bit of a long post but I hope someone can enlighten me on my situation. I've done a search but seem to be running out of ideas.

I’ve got a RB20 with 185,000km’s on the engine and there is a large amount of blue smoke coming from my exhaust when my car is on boost. It started two weeks ago and has been so bad I have been unable to drive the car.

It started after I changed my oil and oil filter. After filling the car with new oil I let it sit for an hour or so and came back to check the level and for leaks. I noticed I over filled it and there was oil leaking from the exhaust side of the turbo. I let some of the oil out so it was at the correct level. Upon start up a large amount of white smoke came from the exhaust which turned to blue after a minute or so. I figured this was just the oil that leaked into my exhaust when I overfilled it. I let the engine warm up and let some of the excess oil burn off. I took it for a slow drive around the block and the blue smoke seemed to stop. I then took it for another drive, a bit harder this time and could see a heap of blue smoke coming out of the exhaust when on boost, so much so that the street behind me was a filled with smoke. It felt as though there was a loss of power and there was a very strong smell of burnt oil throughout the car.

I thought it was going to be my turbo seals so I bought a second hand turbo off here and put it on. The old turbo had a fair bit of shaft play and sounded like it was on the way out. The new turbo had very little shaft play and seemed to be in better all round condition. I took it for a drive and the loss of power and smoke was no better than the first turbo.

Since then I have done a compression test and I got 140,130,120,125,125,125 across the cylinders from 1 to 6 which to me seems ok as there is not a large drop in any of the cylinders. I also took out the PCV valve to make sure it was not blocked, it wasn’t but gave it a clean out anyway. When I took the turbo off there was a thin film of oil in the intercooler piping but nothing out of the usual. Spark plugs 1 & 2 had oil on them and there was also some oil in the spark plug wells. My oil catch can indicates that there is a fair amount of oil going in there.

Any ideas on what my problem could be? Did I buy a dodgy second hand turbo or will I require a rebuild?

Anything else I should check out?

Thanks for your help.

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cabbie_bro Enthusiast

cabbie_bro

Posted
Posted (edited)

To me it sounds like piston rings. Anyone concur?

either that or oil is getting into your fuel supply at some point causing oily plugs and excess oil being burnt in the exhaust. in that case it could be too much oil around your cams - probly on the intake side (cause you got oil on your plugs)

Which Plug(s) came back with oil all over them? going by your compression it could be cyl 3.

Edited by cabbie_bro
moonie Rookie

moonie

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  • Author
Posted
To me it sounds like piston rings. Anyone concur?

either that or oil is getting into your fuel supply at some point causing oily plugs and excess oil being burnt in the exhaust. in that case it could be too much oil around your cams - probly on the intake side (cause you got oil on your plugs)

Which Plug(s) came back with oil all over them? going by your compression it could be cyl 3.

Plugs 1 and 2 had oil on them. Plugs 3-6 were clean.

Could excess oil around my cams be linked to faulty breathers or oil catch can? Or blocked hoses not allowing the excess oil to exit the system?

tridentt150v Grand Master

tridentt150v

Posted
Posted

I can't see how you could have oil leaking from the turbo, even if you did overfill the oil, it shouldn't leak there. If you started it up while it was overfull then you could get that symptom, but once you drain it and set the correct oil level it should clear. The only think you say you did was do an oil change and bam! you have blue smoke that you didn't have before. An oil change won't do that on its own. You could have blown the turbo seal, and the other turbo could also have a blown seal as well, but that is a long odds coincidence. And oil in the spark plug wells???? you haven't cooked the motor have you? a cracked head could do it.

I'd be rechecking your oil level and making sure it is correct first, and assume that the oil in the spark plug wells is spill from when you filled it.

moonie Rookie

moonie

Posted
  • Author
Posted (edited)
I can't see how you could have oil leaking from the turbo, even if you did overfill the oil, it shouldn't leak there. If you started it up while it was overfull then you could get that symptom, but once you drain it and set the correct oil level it should clear. The only think you say you did was do an oil change and bam! you have blue smoke that you didn't have before. An oil change won't do that on its own. You could have blown the turbo seal, and the other turbo could also have a blown seal as well, but that is a long odds coincidence. And oil in the spark plug wells???? you haven't cooked the motor have you? a cracked head could do it.

I'd be rechecking your oil level and making sure it is correct first, and assume that the oil in the spark plug wells is spill from when you filled it.

Checked the oil level several times and its half way between the low and high marks. I used a funnel when filling it so there were no spills. Its not the first time I have noticed oil in the spark plugs well either. In the past it has only been spark plug 1 not 2 as well.

But now that I think about it I had it up on ramps when changing the oil and took it off the ramps before checking the level and noticing the oil leaking. Would turning it on to move off the ramps whilst overfilled blow a turbo seal? And as you said its long odds that the second turbo was a dud. Could moving it this far done any other damage to the engine?

I should also add I had a mate drive it and followed him and there is no smoke when starting the car or on warm up but under load and when stopping after being under load there is a heap of smoke.

Edited by moonie
  • 2 weeks later...
tranman Enthusiast

tranman

Posted
Posted (edited)

I would also bring into question the oil stem seals which would explain why oil is seeping into the the combustion chamber from the around the cams. But those symptoms you described above with your mate driving does sound like a case of the rings.

Edited by tranman
  • 3 months later...
DaShMiEsTeR Enthusiast

DaShMiEsTeR

Posted
Posted
Checked the oil level several times and its half way between the low and high marks. I used a funnel when filling it so there were no spills. Its not the first time I have noticed oil in the spark plugs well either. In the past it has only been spark plug 1 not 2 as well.

But now that I think about it I had it up on ramps when changing the oil and took it off the ramps before checking the level and noticing the oil leaking. Would turning it on to move off the ramps whilst overfilled blow a turbo seal? And as you said its long odds that the second turbo was a dud. Could moving it this far done any other damage to the engine?

I should also add I had a mate drive it and followed him and there is no smoke when starting the car or on warm up but under load and when stopping after being under load there is a heap of smoke.

any news on this?

I know that with time the spark plug looms get a little brittle from the amount of heating up and cooling down they do. Try replacing the loom ? ($200 from Nissan or a lil less from Autobarn) I know it should have come up on the compression test but sometimes you need the timing light to check the spark on each coilpack. Are you running aftermarket coilpacks?

an update would be great.

cheers

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