Smoke out the tailpipe. Source?

Ok, a couple months ago my son and I started running his '89 Daytona 2.5L turbo intercooled. Head is ported and has +1mm valves. The head was milled for flatness when the valve job was done.

Ran it for several months then the turbo stopped spooling. So we pulled the head and put a stock Garrett turbo on. One gotcha was the compressor housing clocked incorrectly and prevented the head from seating. We discovered this after starting to torque it. Untorqued the head bolts, clocked the turbo and retorqued the headbolts. (also put in a new tank, fuel pump and level sender.) Ran it that way for several days, then just as he got to school one day he noticed a cloud behind him.

The cloud looks white, but it lingers... So I am not sure if it is coolant or oil. He did notice the coolant blowing out of the radiator cap when he popped the hood. I wasn't 100% sure, but sounded like a blown headgasket... So we put a fresh headgasket on it. The headgasket looked ok. There was a lot of oily residue on the exhaust output of the turbo. I also noticed that the turbo had a lot play in the shaft on the compressor side. Looking up stream there was some on the exhaust-to-turbo junction. Pulling the turbo and there was a lot of oil in the exhaust manifold.

So I decided that the turbo was not this problem, but likely would have to be replaced soon. So I moved ahead with putting things back together. Initially thought things were fixed. I forgot to connect the TPS and IAC so the engine was racing (~2500 RPM) and there was a little smoke at start, but it seem to clear up. After connecting the TPS and IAC and restarting the smoke was definitly back...

So on to more diagnostics. I pumped up the cooling system pressure to 10psi. It held for more than 10 minutes. Started the car and noted that pressure did go up to 12psi. Shut the car down and let it sit. 5-6 hours later the pressure in the system was 5-6psi.

So I am thinking that despite the smoke appearing white (ie. coolant) it is actually oil. Then question is what is the source?

My thoughts questions right now are:

Can a turbo sling oil back into the exhaust manifold?
Would a bad valve stem seal cause a lot of white smoke? didn't see much residue in the cylinders, so I am guessing it is not the intake valve stem seals..

Any thoughts or opinions?

White smoke out the exhaust to me means I'm burning water NOT OIL AND DEFINITELY NOT GOOD. If you were burning oil it would be gray, or if you were burning ah bunch of oil it would be closer to black. My guess is you either have a bad head gasket or (and I hope for your sake) you do not have a crack somewhere in the head that's letting antifreeze get run through one or more of the cylinders and out the exhaust, Jer

ifthe oil fill cap is off will the engine blow smoke out the valve cover? if so maybe cracked ring lands

If you start up the car and it doesn't smoke until it's warmed up, you're probably dumping oil into the exhaust from the seal on the turbine side of the turbo. Check the plugs for oil on them. If there's not any on there it's almost certainly the turbo.

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Originally Posted by bigbarneycars

White smoke out the exhaust to me means I'm burning water NOT OIL AND DEFINITELY NOT GOOD. If you were burning oil it would be gray, or if you were burning ah bunch of oil it would be closer to black. My guess is you either have a bad head gasket or (and I hope for your sake) you do not have a crack somewhere in the head that's letting antifreeze get run through one or more of the cylinders and out the exhaust, Jer

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Not sure if I believe all of that. Ever see a car with bad valve guide seals? The oil smoke is often white with a blue tinge. This looks like that smoke minus the blue tinge...

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Originally Posted by boost geek

ifthe oil fill cap is off will the engine blow smoke out the valve cover? if so maybe cracked ring lands

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No. There is a mini-cone filter on the PCV port and no smoke comes out...

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Originally Posted by cordes

If you start up the car and it doesn't smoke until it's warmed up, you're probably dumping oil into the exhaust from the seal on the turbine side of the turbo. Check the plugs for oil on them. If there's not any on there it's almost certainly the turbo.

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Smoke starts within a couple seconds of starting the engine...

All the plugs look fine and the same, but there is very little run time with the car like this (definitely a sudden onset.) The engine/turbo is putting out a LOT of smoke and it lingers...

I am leaning toward the turbo because of the excessive play on the compressor shaft... I dismissed it initially because I didn't think the turbine wheel could sling oil back into the exhaust manifold.

I am toying with disconnecting and plugging the oil supply line and starting the car...

Thanks
Ed

Make sure the oil return is completely free of obstruction. If the oil can't drain properly, it can cause smoking issues. If you used any sealer, it can restrict the line and cause problems.
Why not just get a turbo rebuild kit and eliminate it as a possibility. I have rebuilt a couple turbos, and they all are still working to this day. One has over 10k on it. For about $80, you can eliminate one source of oil and possibly solve your problem.
Running the turbo without oil may cause damage and make it costlier to rebuild

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Originally Posted by boboli

Running the turbo without oil may cause damage and make it costlier to rebuild

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Not talking about driving it, just idling it for a minute or so... Likely less given how quickly the smoke starts...

Smoke within seconds of cold start up is usually not a turbo issue. Oil/coolant is present in combustion chamber before the turbo.

Which fluid is low, coolant or oil? Question answered. For quicker answer place clean white cloth over tailpipe. Is the residue oily or the color of the coolant?

Chris-TU

I had a valve stem seal lift off the guide a few minths back. Its easy to visually check that as in my case the guide dropped and the seal was up on the valve stem.