Blue smoke after boost....turbo seals?

[tooch]

Hmm another thought after reading another thread, could my dodgy catch can be causing this in any way?

[o_man_ra23]

I was under the impression that(logically) the plumback air would be dumped back into the exhaust manifold to alleviate air pressure differentials. This would also cause the car to run rich, but then the fuel would probably ignite when it got to the exhaust manifold, and then the rapid expansion of the air would accelerate the turbine much like in a rally car... hmm... something to think about there... I suppose that for that reason, dumping the air back in before the compressor would work also, just wouldnt stop the pressure differential problems which would play havoc with a worn turbine bearing seal.

Cheers, Owen

[EldarO]

I was under the impression that(logically) the plumback air would be dumped back into the exhaust manifold to alleviate air pressure differentials. This would also cause the car to run rich, but then the fuel would probably ignite when it got to the exhaust manifold, and then the rapid expansion of the air would accelerate the turbine much like in a rally car... hmm... something to think about there... I suppose that for that reason, dumping the air back in before the compressor would work also, just wouldnt stop the pressure differential problems which would play havoc with a worn turbine bearing seal.

Cheers, Owen

you mean cheap anti-lag...?

i know that an atmo valve on an AFM car screws with it royally, but it may just be that your oil seals are on their way out, but its not that bad, and only evident at 10psi?

my reccomendation would be to turn the boost down so the car doesnt smoke, then be happy

Eldar.O.

[tooch]

That's stock boost dude!

[mullett]

Yes, it could be a catch can for sure. I just fixed exactly the same problem with a friends skyline. If you've plumbed your breather into a catchcan, the catchcan MUST be able to breath, or you're generating excess sump pressure. In his case, there's 2 breathers on the 2 rockercovers, so he put each to one of the outlets on the catchcan. End result, blew oil into the intake. Make sure your head can breath!

[Jorrs]

i have a venting BOV on my car and its AFM and its fine ??

[mullett]

I don't think you could dump BOV air into the exhaust manifold, even at idle there'd be far more pressure in there than a humble turbo would produce...you want your BOV to dump somewhere where there's no pressure, to keep the turbo spinning. If it's gotta work against pressure, it'll stall anyway...

RM.

[EldarO]

That's stock boost dude!

im used to stock 7M CT26 of 6psi i guess!

fark, then you have a problem...

i was under the impression that black smoke was oil, blue smoke was fuel (or do i have them the wrong way around...?) and white was water, ala BHG, ala what just happened to my car.

assuming the smoke is fuel, then your massively overfueling, and the ECU maybe dumping fuel into the engine to protect it because it thinks it in danger of shitting itself.

assuming its oil, your turbo seals maybe rooted, but that doesnt explain why it would only do it at high boost...

are you sure its only doing it at 10psi, and not at any lower levels...? maybe your just not noticing..?

Eldar.O.

[tooch]

Blue smoke=oil, and yeah its definitely only doing it at the higher boost levels, there is a HUGE blue cloud out the back after I back off, its very noticeable.

[o_man_ra23]

I don't think you could dump BOV air into the exhaust manifold, even at idle there'd be far more pressure in there than a humble turbo would produce...you want your BOV to dump somewhere where there's no pressure, to keep the turbo spinning. If it's gotta work against pressure, it'll stall anyway...

RM.

yes there is pressure in the exhaust manifold and all that... BUT... the inertial of the now freewheeling turbo turbine will make it act like a compressor, sucking almost as much air as it was previously being pushed by... BUT, now there is less air to suck as the throttle body is closed, and minimal air is going into the combustion chamber. SOOO... this will create a vacuum in the exhaust manifold between the throttle body and the turbine wheel, as the turbine is trying to suck air which isnt there... sooo... if the compressed air from after compressor wheel is now directed into the manifold which has a temporary vacuum, it allows the turbo to continue spinning at speed, while alleviating the strain on the bearing seal which relies on manifold pressure to keep from leaking. If this vehicle is also fitted with an AFM, then the ECU still thinks its getting air in, and will fuel accordingly, and that fuel will mix with the freshly vented air in the hot exhaust manifold, and ignite, which will cause manifold pressure, and spin the turbo quicker, thus you now have antilag...

Personally I wont be trying this setup on my 3SGTE when i get it, though i may look at buyin some cheap ass turbo motor later on and playin around with it. It will be harsh on turbos... perhaps ceramic turbos will handle the heat better though even though they cant produce as much pressure?? If you dont have an AFM, then the motor wont fuel up, and as such, you wont get the antilag effect. Food for thought there. If anyone tries this, let us all know how it goes.

Cheers, Owen

[Hydra]

When the seal went on one of my turbos, just driving around resulted in plumes of oil smoke Lotsa fun! Took it down to the shops too and did my weekly shop in it just for a laugh.

Can you try a 2nd turbo out? Maybe find someone willing to spend the time swapping turbos however hard it might be in that tight little engine bay.