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Discussion Starter #1
Hey guys,

Help me to diagnose this here. The car was smoking like crazy, so I had the valve guide seals replaced, and changed the weight of the oil to 15W-50, and it still smokes badly. Now we've narrowed it down to two things. Fried piston rings, or bad turbo seals.

The motor has about 4-5000 miles on it, and runs strong.

The turbo is basically new, it sat for a year or so before use, but runs strong also.

One thing is that when we sat the turbo on it's tubine housing, it started to leak oil out of the back, and onto the floor. Is this normal?

Thanks in advance guys,

Eric
 

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I've never had a turbo leak oil out of the back....
 

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Discussion Starter #5
Hmmm...I'll try the oil cap off trick.. Which filter would you be talking about though? The PCV valve, or the oil fill hole? I'm thinking the turbo might be shot also, and it's a real shame since it's only seen 13psi.

Eric
 

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Eric,

Is your turbo DBB?

Ken.
 

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Discussion Starter #8
The turbo isn't a DBB, I got it January 2004, and it sat until a couple months ago.

The smoke doesn't start unitl the car is warm, and stops for the most part only when the car is damn hot. Until it's very hot, it smokes like crazy.

Eric
 

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My money is on the turbo
 

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cowboy bebop said:
Hmmm...I'll try the oil cap off trick.. Which filter would you be talking about though? The PCV valve, or the oil fill hole? I'm thinking the turbo might be shot also, and it's a real shame since it's only seen 13psi.

Eric
The oil fill hole.

I think I fried a turbo in about 30 seconds so, it happens.
 

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Eric, i would do a leakdown test. This will let you know where you stand as far as your shortblock and give you some peace of mine. Even if it turns out to be the turbo, you still know where you stand with your shortblock
 

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Are you valve guides cut?? I had the same issue in my car where it would smoke.. I took the head off and saw that the Custom Bronze valve guides were loose which was causing the valve seals to pop up causing the smoke.. The machine shop didn't install the guides properly etc causing the smoke.. I would also recommend using Valvoline 20w50 NON SYNTHETIC oil.. Best oil I have ever used. It stopped my valve seal issue on my other supra.. Good luck..

Sherbaz
 

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chevyeater-on-sf said:
or, just take the oil filler cap off with the engine running. If the rings are wasted, there will be smoke coming out of the filler. My money is on the turbo.
I was checking the fluids on my car last night and took the oil filler cap off for some reason. The engine was off, but had just gotten back from a short drive and if I looked closely, I could see a little vapor (like a slight steam vapor then smoke). Is that normal or should I be worried?

Brad
 

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A little vapor isn't a concern. Perhaps your oil temperatures are a little high or there was some water in your crankcase from the car sitting. If you aren't sure what you are looking at, a leakdown test would give a cut and dry yes or no answer.

If your rings are shot enough to smoke out the tailpipe, it will be clearly evident when you pull the cap off with the engine running.
 

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i wouldn't put my money on the turbo. Its prob the PCV valve, i had my valve stem seals replaced and then it still smoked, so i took it to a shop, and they found the pcv valve, and a line running from it, to be clogged with oil. On a side note tho, they took off the head to see if it was the valve guides and it turns out the guy i bought my car from (the original owner) didnt maintain it properly, so the pistons look like ashtrays and the crankshaft and camshaft are caked/gummed with oil :(
 

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chevyeater-on-sf said:
A little vapor isn't a concern. Perhaps your oil temperatures are a little high or there was some water in your crankcase from the car sitting. If you aren't sure what you are looking at, a leakdown test would give a cut and dry yes or no answer.

If your rings are shot enough to smoke out the tailpipe, it will be clearly evident when you pull the cap off with the engine running.
Thanks for the reply. I haven't noticed any smoke coming out the tailpipe, but have lived that scenario already and now have ~700 miles on the rebuild and am a little paranoid. That can happen when you experienced what I did after my build-up: TC fails and damages your new built tranny, your turbo fails 3x's and your motor is toast (2 bent rods) all in less than 250 miles from picking-up the car :(

Thanks,
Brad
 

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Discussion Starter #17
It's wierd because it'll smoke after it warms up, but after a while it goes away pretty much. I did switch recently to 15W-50 oil, and I can notice the difference. The car runs strong, but I am apprehensive to dyno any longer and for more HP until we figure this problem out.

Eric
 

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Doesn't sound like the turbo to me but, under the circumstances, it would be great if it was. As has been noted, compression/leak down is what's needed here. I don't mean to be an alarmist, but it's sounding more and more like poor ring sealing to me. By your own accounts, you haven't run enough boost and rpm (assuming a safe tune) to beat your rings to shit. Did you take off your turbo yet and inspect the inside of the manifold? I wish you all the luck.

Ken.
 

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Discussion Starter #19
I looked in the manifold before we put the turbo back on and it had the normal blackness that you'd find with burnt fuel, but I didn't see any oil. The turbine housing of the turbo however was covered in it when we sat the turbo down on the floor while we worked on the car. It was leaking onto the shop floor, in fact. I asked Larry at SP, and he said it was normal for turbos to do this, however. Right now, this is what happens. The car starts and there is no smoke. WHen the car is moderately warm, it smokes a lot, to the point where people next to me at the stop light roll up their windows. When the car is up to temperature, the smoking stops it seems. Keep in mind too, that the valve guide seals have been replaced.

Eric
 

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This actually sounds like my car. When I start it up and oil pressure is high, I get some oil leaking on the back side of the turbo. As it heats up enough the oil will burn off then it's not really noticeable after that. Once the oil pressure drops down it doesn't leak nearly as much.
 
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