What's This White Smoke?

[Andrew.Y]

My car did this on the first run... Then off the dyno.

White smoke coming out. Knocking reached 100. Oil motul 10-40W. Stock engine 18 psi. Still drives fine on the street even @ 8000RPM knocking is under 25.

What's wrong with it?

http://www.youtube.com/watch?v=l_IbCyveaa0

[Gareth87]

It seems as though the smoke is on decel and therefore full vacuum.

You could have a turbo oil seal problem or stem seals, that would be my first guess.

My engine did a similar thing when i ran gapless total seal rings in it, but as your engine is standard, obviously that gets ruled out.

Is there any chance that could be steam? if water is making its way into the cylinder you may see that. I would think its unlikely though.

Im sure others will comment but that my 2 cents.

G

[DVS JEZ]

I agree with the above post. Valve stem seals. I saw this on 2 gtr's the other weekend at a hill climb. On the decent back down they were both pumping out the same smoke. Cleared up when revved. 1 had a stock motor the other had built 30/26

[James_03]

Don't think it would be turbo, you would see white smoke before decel when the oil pressure is at peak.

That's when it will bypass the seals. Does it do that all the time? or was that just a once off?

If all the time I would be inclined to think stem seals as above.

[hypergear]

It looks like oil drainage issue caused from excessive crank case pressure, which forced out of the turbine seals along with few drops of oil.

[Piggaz]

I agree with the above post. Valve stem seals. I saw this on 2 gtr's the other weekend at a hill climb. On the decent back down they were both pumping out the same smoke. Cleared up when revved. 1 had a stock motor the other had built 30/26

better not have been mine!!!!! haha

[GTRsean]

Oil going into combustion chamber from PCV valve on decel/vacuum. Caused by oil build up in the pipe from the RH rocker cover pipe to the PCV. Valve is closed under boost, a little oil builds up in pipe, you back off, valve opens and oil goes to hot exhaust side and smokes up.

Also agree it could be valve stem seals though.

[DVS JEZ]

better not have been mine!!!!! haha

Haha nah Paul not urs. Steve's was pumping it out on decel and so was deano's. But after a couple of revs it was all clear.

[Beer Baron]

bit of a tough one. the big puffs of black smoke like that are usually detonation but then the big spray of white following is oil burning. I don't have sound hear so a bit hard for me to see when exactly during the run the smoke occurred but crank case pressure or valve stem seals is a possibility as i a blow turbo oil seal but the big gulps of black smoke first is usually a big detonation event/missfire. how is the car running now? what's the idle like? any further smoke?

[DVS JEZ]

Big call saying detonation. Its possible but its a big call. More likely a missfire of sorts

[R31Nismoid]

Oil going into combustion chamber from PCV valve on decel/vacuum. Caused by oil build up in the pipe from the RH rocker cover pipe to the PCV. Valve is closed under boost, a little oil builds up in pipe, you back off, valve opens and oil goes to hot exhaust side and smokes up.

+1

Although surely the guy running the car up said that

[Andrew.Y]

Thank you all very much guys. Thank you for spending your time and effort and knowledge on this topic. Thanks a lot.

The car is driving OK on the street, knocking less than 30. Not much smoke from the exhaust. I think it only did it on the dyno.

Castrol Edge 10-60w was used, however this time I just want to try different product so I used motul 8100 10-40w. the day before the dyno I thought the oil might be a little bit low so I added about 1/2 litre of Mobile 1 0-40w as I don't have other oil around.

I think the oil is a bit too thin. But I don't know whether the thin oil did such damage.

[Beer Baron]

mixing oils is not such a great idea. but the big cough of black smoke is what worries me. what did the operator say when it happened? just to be cautious I would spend 30min doing a compression test and leak down test too. if there is something wrong you want to know about it now. no point just letting it go crossing your fingers that it's ok only to have it let go in a big way a month from now. that amount of black and then white smoke is not normal on the dyno so something happened. you just need to find out what.

[joeyjoejoejuniorshabadoo]

the thinner mobil oil won't be affecting it unless you are flogging it before it's up to temp, which i'm guessing you are not doing

the 40 weight is a little too thin for an RB that is getting up to 8000 revs. stick with the castrol edge 10w60 or if you want to switch to motul go the 8100 15w50 if it's street driven or 300v 20w60 if it's a purely track car

[femno]

You cant compare street VS dyno because you would never see some of the loads you see on the dyno. Not for a quick squirt in 2nd or 3rd anyway. SO dont assume its fine.

Black smoke / knock could be plugs or coilpacks shitting themselves up top. If not those something more serious.

Because youre running 18psi, my bet is what Sean is saying. The oil is building around the PCV and then on decel it sucks the oil into the engine via the PCV. I had the same problem around the track, every gear change id have a massive plume of smoke from the exhaust. It was the PCV sucking oil from the rocker at constant high revs.

Try blocking the PCV and removing the recirc to the rear turbo to check if it goes away. You may also need to remove the resistrictor in that recirc hose to let the engine breathe a little better.

Surely the dyno operator suggested all this?

[Andrew.Y]

You cant compare street VS dyno because you would never see some of the loads you see on the dyno. Not for a quick squirt in 2nd or 3rd anyway. SO dont assume its fine.

Black smoke / knock could be plugs or coilpacks shitting themselves up top. If not those something more serious.

Because youre running 18psi, my bet is what Sean is saying. The oil is building around the PCV and then on decel it sucks the oil into the engine via the PCV. I had the same problem around the track, every gear change id have a massive plume of smoke from the exhaust. It was the PCV sucking oil from the rocker at constant high revs.

Try blocking the PCV and removing the recirc to the rear turbo to check if it goes away. You may also need to remove the resistrictor in that recirc hose to let the engine breathe a little better.

Surely the dyno operator suggested all this?

Oil catch can is installed by the time the car is on the dyno. So i guess there is no oil taken from the intake pipe.

Operator didn't mention much. Spark Plugs fitted less than 3K and spitfire coil packs fitted as well.