I think that the lack of a vent in the turbo drip tank in aftermarket headers (like B&B or GHL) can cause smoking on a startup following a drive. Has anyone come to the same conclusion?
I installed aftermarket headers without a vent and I'm now getting a lot of blue smoke whenever I start up after its been sitting. I think the vent-less configuration lets oil flow without issue, but when the engine is turned off, a vacuum is created that pulls oil from the engine into the turbo. The excess oil stays there until you restart the car, and then it’s burned off.
Here are some tests that I’ve done
1. Checked to ensure scavenge pump is working and oil is flowing when engine is running. I disconnected the oil tube at the drip tank and connected a short tube to the tank nipple to let oil flow into a clean glass pitcher. I placed the scavenge pump intake oil line into the same pitcher (see picture). I started the car, revved it quite a bit for a while and the oil level in the pitcher stayed constant at the level of the scavenge pump intake – as expected. Conclusion: Oil circuit works correctly.
2. Ensured turbo seals are not failing. After a run, I thoroughly drained the oil from the drip tank and turbo. I restarted the car and there was no smoke, not even during a spirited run. I let it sit and then restarted the car – I got huge billows of grey smoke for an extended time. Conclusion: Turbo seals are fine (otherwise it would smoke during all runs) and teh turbo is filling with oil with the engine off.
I've heard that the ball bearing in the oil feed line circuit is suppose to act as a check valve to keep this from happening - can anyone confirm this?