Smoke coming from Exhaust,Valve Stem seals? (SR20DET)

[jerryscherry]

I'm having blueish smoke come out from my exhaust during cold starts, and will keep coming out until after 5-10 mins of driving. Usually by the time I get to the freeway for work it will usually disappear. It will come back sometimes in stop and go traffic. There is evidence of oil consumption but nothing too dramatic.

I'm currently still breaking in the motor (350miles) and it so far after 5-10 mins of driving, it will not smoke during boost (5psi). I haven't gone over 5psi yet since i'm still breaking in the motor. There was one puff of smoke during initial break in, and at about 60 miles there was another puff of smoke, then eventually it started smoking in the morning , like it was gradually getting worse.

Leakdown test revealed 3-4% across. When motor was rebuilt, turbo looked clean and free of oil. PCV valve was also changed about 50 miles before my motor blew. However my head was left untouched besides gaskets and the lifters being flushed.

My theory is since the head has been sitting for about 2 weeks while the motor was being in the machine shop and assembled, the valve stems probably dried out and the seal gradually got worse with more miles being put on it.

Any other thoughts or ideas of what could be causing the smoking?




SR20DET Redtop Overbored 86.5mm
Supertech Forged pistons 86.5mm
Oem Rods
ACL Bearings
Oem Gaskets all around.
GT2871R 0.64 AR
Head was untouched.

[Kingtal0n]

Ive heard of people using the wrong valve seals during their rebuild by accident, but you said the head was untouched.

To be honest i would instantly suspect your oil feedline has the wrong restrictor if this issue suddenly cropped up when you installed the turbo. Especially if you bought lines from ebay, I See them selling the wrong lines all the time for that turbo.

Where else can oil come from?
It can pass the valve, you know that.
I can pass the piston ring, you know that.
It can pass the turbine, you know that.
It can pass the PCV port, you know that.

How about the valve cover itself? Did you weld on it? How is the internal baffle? S13/S14? Either way, I would certainly check all around the valve cover ports, all of them, There are 2 of them, for evidence of oil.

If it isn't blowing oil everywhere when you boost, that is a good sign. It more points towards the valve seals, and turbine seal, than the rings at least.
I think the MOST important thing besides the turbo atm, is to check inside each cylinder (PULL THE PLUGS ASAP) for evidence. You need to know right away if its actually burning the oil, or if the oil is just entering the exhaust and THEN burning.

[jerryscherry]

Ive heard of people using the wrong valve seals during their rebuild by accident, but you said the head was untouched.

To be honest i would instantly suspect your oil feedline has the wrong restrictor if this issue suddenly cropped up when you installed the turbo. Especially if you bought lines from ebay, I See them selling the wrong lines all the time for that turbo.

Where else can oil come from?
It can pass the valve, you know that.
I can pass the piston ring, you know that.
It can pass the turbine, you know that.
It can pass the PCV port, you know that.

How about the valve cover itself? Did you weld on it? How is the internal baffle? S13/S14? Either way, I would certainly check all around the valve cover ports, all of them, There are 2 of them, for evidence of oil.

If it isn't blowing oil everywhere when you boost, that is a good sign. It more points towards the valve seals, and turbine seal, than the rings at least.
I think the MOST important thing besides the turbo atm, is to check inside each cylinder (PULL THE PLUGS ASAP) for evidence. You need to know right away if its actually burning the oil, or if the oil is just entering the exhaust and THEN burning.

I forgot to add I was using the same turbo before I blew my motor and it was fine. im using a 0.04 restrictor
http://www.frsport.com/DIF-10016-Turbo-Oil-Restrictor--3AN-to-7-16-24---04--Oil-Hole-Size-_p_16397.html

I had my friend drive behind me on the freeway, and he said the smoke was not consistent , it would disappear for 5-10mins then come back for a few mins and disappear, my speeds were around 45-65 due to heavy ass rain.

my mechanic took a look pulled out the plugs and said only one spark plug (cylinder 1) was black, so assuming only one cylinder was burning oil. he dried out cylinder 1 and let it sit, no oil. then ran it for about a minute and there was a lot of oil on the piston, saying it was too much for just being seals. was thinking maybe the Oil ring didn't seat properly? since leakdown/compression doesn't test for the oil ring, only the piston compression ring.

FML........

[Kingtal0n]

I forgot to add I was using the same turbo before I blew my motor and it was fine. im using a 0.04 restrictor
http://www.frsport.com/DIF-10016-Turbo-Oil-Restrictor--3AN-to-7-16-24---04--Oil-Hole-Size-_p_16397.html

I had my friend drive behind me on the freeway, and he said the smoke was not consistent , it would disappear for 5-10mins then come back for a few mins and disappear, my speeds were around 45-65 due to heavy ass rain.

my mechanic took a look pulled out the plugs and said only one spark plug (cylinder 1) was black, so assuming only one cylinder was burning oil. he dried out cylinder 1 and let it sit, no oil. then ran it for about a minute and there was a lot of oil on the piston, saying it was too much for just being seals. was thinking maybe the Oil ring didn't seat properly? since leakdown/compression doesn't test for the oil ring, only the piston compression ring.

FML........


Wow thats rough. theres a long list of problems associated with attempting a rebuild on any engine. Maybe somebody just forgot to dis-align the gaps? If so, it might clear up gradually as the rings spin in the bore. I mean if you are not going to rip it apart. Although, it is not a good idea to try making any kind of power with oil in the cylinder. Oil acts like liquid and does not compress, raising your compression ratio, it is associated with detonation frequently.

I am thinking about this more. If it comes and goes.. try to find out what makes it come back. When you compression brake for instance, try 5th gear from 80mp to 45mph compression braking. Then get back on the gas and see if a cloud of smoke shoots out the exhaust.

[jerryscherry]

Wow thats rough. theres a long list of problems associated with attempting a rebuild on any engine. Maybe somebody just forgot to dis-align the gaps? If so, it might clear up gradually as the rings spin in the bore. I mean if you are not going to rip it apart. Although, it is not a good idea to try making any kind of power with oil in the cylinder. Oil acts like liquid and does not compress, raising your compression ratio, it is associated with detonation frequently.

I am thinking about this more. If it comes and goes.. try to find out what makes it come back. When you compression brake for instance, try 5th gear from 80mp to 45mph compression braking. Then get back on the gas and see if a cloud of smoke shoots out the exhaust.

thanks man, had my mechanic took a look at it and it was cylinder #1 oil rings. He cleaned out cylinder 1, and started the car, and oil filled up cylinder 1 pretty quickly. took it apart put in new rings, seems to be okay right now after break in. no smoke whatsoever. :) , also had new valve stems installed anyways, but it was way too much oil for just stems.

weird how the smoke would go away sometimes, because to my knowledge, if it was rings, it would be more consistent smoking.

oh well all good now :)