Smoking from catch can and turbo?
 

Hello,

I have a iag stage 1 with a jdl turbo. I went for a small drive and saw smoking coming from under the hood. Headed back home and opened the hood to see a smoking turbo. I later noticed the smoking was also coming from my catch can (full blown motorsports). It was a leisure drive without going into boost. My pcv valve is a straight thru fitting and catch can is VTA.

Looks like I have excessive crankcase pressure or a leaky turbo.

I heard that is normal for some VTA catch can systems to smoke but it seemed like alot and smoking was also coming from the turbo
Any ideas or advice?

when you say smoke coming out of turbo you mean coming out from the intake side, Where the air filter is?

also, with aftermarket pistons you get more blowby and personally i would prefer to have a real pcv, possibly also with an extra oneway valve in series to have less pressure in the crankcase and make the vent System working good

I think the smoke is coming from the crankcase via the oil drain on turbo. It looked like the smoke was coming out of yhe turbo, chra, but mostly the turbine side. My air filter is on directly on the turbo. I verified the smoke coming from the CCV side.
Yea i actually had the STI pcv valve on there before i install the full blown catch can system.

Ill post vids later when im back home.

Are you sure oil is draining from turbo?

i believe so.

https://www.youtube.com/shorts/QV5WLxWcj3s

i think it might just be residual oil thats was spilled. i'll see how it looks tomorrow

Honestly that is a lot of smoke to determine where it is coming from. Is this your first start up? My car smoked the first few times after super charging it from the oils that were on everything.


Catch cans should be presurized and sealed on a boosted setup so if smoke is coming out of them you have other issues too.

You may want to check if you can see some oil residue somewhere on the turbo or any of the connections to it. It happened to me once where one of the fitting was slightly loose and there was just enough oil seeping to cause smoke. It got tightened up and solved the issue. Another potential issue I’ve seen is a case where too much crank case pressure causes the oil in the turbo to not drain properly and eventually leak through the turbo seals. With higher power levels, higher cc pressure can cause this, and cc ventilation can be somewhat tricky to achieve. Personally When my block was built, a regular pcv such as an sti one was not adequate and I had to move up to an adjustable pcv with dual AOS setup and closed ventilation to work things out. Good luck.

There should be no appreciable level of CC pressure sitting at idle, with VTA or a sealed PCV system. Unless you have BIG engine problems, or something with the PCV system is improperly plumbed.

Although, that vid shows what looks like oil on external surfaces of the turbine? Could it have been spilled and under a heat shield? Might just take some time to burn off. Or, remove the shielding and inspect/clean. Could be a loose supply line or fitting too.

Would be nice to see a diagram and pics of how the catch can is set up. IMO, a sealed PCV system (stock or aftermarket) is much more beneficial than VTA, regardless of boost/power.

Best practices for turbo drain/plumbing...

-The drain port/lines need to be AT LEAST as big as the drain port on the turbo.

-Drain line should ONLY go downward, with no horizontal routing (unless scavenge pump is used).

-Drain line into the engine/sump should be above the oil level when the car is idling.

-Turbo sump must be vented to the engine's PCV system. If it's not, you can absolutely push oil past the turbo seals under some conditions, but there would be no external smoke at idle.

- If the turbo is low and using a scavenge pump, a 1psi check valve to prevent overfilling the turbo CHRA after shutdown.

.