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Discussion Starter #1 (Edited)
My car has recently started smoking at idle. After I start my car and it warms up a little bit it will begin smoking. When I drive the smoke goes away. However as soon as I come to a stop light it begins smoking again. It smells like burning oil. It drives like normal other than the embarassing smoke.

Do you think it is the valve stem seals? My car has pretty low mileage (40k) However it is 11 years old now. My turbos boost fine and there is NO Smoke while boosting.

Today I changed my oil and filter. The oil looked fine, no metal shavings or anything. I also did pull out my spark plugs and here is what they look like (I sometimes run leaded race gas if that matters):



How do they look?
What do you think would cause the car to only smoke at idle?

Thanks for your help.
 

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If you move around you can smoke away from idle;)
 

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Probably your valve stem seals. I had the exact same symptoms in my car, smoke after 2 minutes from start up and smoke at idle/stops. I switched to 20W50 oil and the smoking stopped. Occasionally if I don't drive for 2 days or so I will smells oil burning just a sec or so after I start it up but it doesn't consume any noticeable oil. Either switch to thicker oil or get your valve stem seals replaced or do what I did for awhile and put teh car in nuetral and keep RPMs at 900-1.1k (ghettoo style) at stops.
 

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ive got the same problem but with only 34k on the motor. i noticed it after a few cold nights of long hwy pulls and boost creeping up to 19-20lbs.
 

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hey bud, sounds like the same with me too...i replaced my seals, havent run the car yet to find out if that fixed it...also, the leaded race fuel will kill your O2 sensors
 

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Yes your stem seals are leaking, but the problem will be worsened if you dont have the stock crankcase vent into the intake. If you've taken this crankcase vent to a catch can instead, put it back to the intake like stock, just run the other side into a catch can, then into the compressor intake.
 

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im curious as to why you think that running a catch can will worsen your smoking problem considering the smoke is from burning oil, running the pcv line directlly to your intake sucks oil into the engine, a catch can is just a separator, it does not increase your crankcase pressure but it does separate the oil from the "blowby" gasses. i would say the reason you are smoking is MOST LIKELY valve stem seals considering it only smokes at idle due to the increased vacuum which is sucking the oil from the head into the intake. when you are boosting it is pushing the oil out of the valve guides so it doesnt smoke. there is a writeup on here letting you know how to replace the seals, i suggest you get a day where you have nothing to do and attempt to do it yourself, just follow the directions very closely, you dont want to drop a valve or shoot a keeper.
 

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Discussion Starter #9
gmacrae said:
Yes your stem seals are leaking, but the problem will be worsened if you dont have the stock crankcase vent into the intake. If you've taken this crankcase vent to a catch can instead, put it back to the intake like stock, just run the other side into a catch can, then into the compressor intake.

I do not have a catch can. My crankcase hoses, PCV and all the other assosiated stuff is completely stock.
 

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SupraDupaFlyBoy said:
im curious as to why you think that running a catch can will worsen your smoking problem considering the smoke is from burning oil, running the pcv line directlly to your intake sucks oil into the engine, a catch can is just a separator, it does not increase your crankcase pressure but it does separate the oil from the "blowby" gasses. i would say the reason you are smoking is MOST LIKELY valve stem seals considering it only smokes at idle due to the increased vacuum which is sucking the oil from the head into the intake. when you are boosting it is pushing the oil out of the valve guides so it doesnt smoke. there is a writeup on here letting you know how to replace the seals, i suggest you get a day where you have nothing to do and attempt to do it yourself, just follow the directions very closely, you dont want to drop a valve or shoot a keeper.
When the car is idling there's around 20psi vacuum in the intake and ports right, the PCV line into the intake de-pressurizes the whole crank case so there is a similar vacuum either side of the intake side valve seals, because of this, oil is not "sucked" into the intake ports. If the car is not running a pcv vent to the intake, the crankcase is not in vacuum at idle and the intake ports suck oil straight thru the tired seals.

So although the main problem is the valve seals (they shouldn't leak in either case), running without the intake PCV line (with PCV valve) will make tired valve seals smoke even more (MUCH more).

Which brings me to another point; At idle, the engine isn't (shouldn't) be creating much blowby, so there isn't much oil mist going into the engine anyway. This combined with the fact that negative crankcase presure is a very good thing (for valve seals, cam seals, crank seals), why would you ever want to get rid of this intake side vent? This vent closes up once the car is on boost, so its the other vent that really matters. It is still a good idea to run the other PCV vent to a catch can, and back to the compressor intake. When i go single, i plan on blocking off the exhaust side PCV vent and instead running a line from the back of each cam cover (tidier) to a check valve in the dump pipe. The intake side PCV vent will stay in place.

Gene
 
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