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Serious Engine Smoking Upon Deceleration


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Ugh, engine problems.

My engine does not smoke on idle or driving. It is clear all the time. When I accelerate its also clear but the past two days I have noticed a billowing of smoke after I let off the gas, decelerating...and not a little. Its definitely oil.

Thoughts? Tests?

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I think this issue is related to your breather setup/PCV. IIRC, Hussein encountered this problem a number of times. I remember reading about it in his build thread.

Running stock setup but it seems odd that it went from nothing to Hello! smoke screen!

Sounds like valve stem seals to me.

Keep in mind the engine is new...everything, including valve stem seals. 5k

I was reading on a Supra forum with someone who had a similar experience and they all agreed this guy had the turbo seal go bad.

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Turbo or pcv is my bet. Any shaft play?

Dont know yet since I just confirmed this was happening today. Yesterdays smoke screen was at night.

Car runs great btw, no signs of anything wrong. I am hoping its the turbo although its a brand new 19T but it would make sense if the seal went and its squirting oil into the hot exhaust manifold that would make tons of smoke.

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If it's the exhaust seal, you will have oil seeping around the CHRA band clamp.

Could easily be crankcase pressure related, or CBV even - I've had several scenarios - BUT - if it's the oil seal on a new(ish) turbo, then you have to look at WHY it failed, typically this will be due to excessive load on the compressor (comp. surge, delayed pressure relief on decel {CBV}, etc. which result in a worn thrust assy, which in turn loads the oil piston ring on the hotside of the CHRA.

Start by removing your dipstick, attach a hose to vent under the engine & drive it. IF you don't have any smoke on decel, your problem is CC pressure.

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Do a leak down test. On my last engine I had something similar with smoke only on decel. Pretty sure it was the rings, cause I rebuilt the turbo and bolted virtually everything including the PCV to the new engine and had zero smoke.

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I did a compression check, its fine. I thought about the open PCV hose but then figured if I pressurize the block it should vent through the PTC. So I applied pressure through the dip stick line. I could hear it blowing in the intake so the PTC is not plugged. Then I got my fingers down by the turbo underneath and there is oil. I am thinking that is it.

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