[mr.bangle3]

So guys, my 07 335 stopped making boost about 3-4 weeks ago, didn't/doesnt make any strange turbo noises. I had just started it up one day, get on her and boom, no boost, still haven't made any since then. My thinking was the waste gates because at the same time the exhaust note changed and engine is running great still. Well now, (I do not daily the car) if the car sits for any period of time, it will smoke heavily for the first few mins of driving then clears up when its warm. The smoke is blue and grayish, I have no codes at all even though im not even making a bar of boost. So obviously something is up with the turbos but the smoke is what's throwing me off because if it were just waste gate problems it wouldn't be smoking correct? Any input is appreciated, sorry for any left out info!

2007 E92 335i MHD stage 2+, XHP stage 3.

[david in germany]

First check the easy stuff, vacuum lines. Start at the vacuum canisters and work your way to the other side of the engine. No vacuum = no boost. If you haven’t done it yet, upgrade all of the lines to silicone lines.
By the way, the reason I said this is when I swapped out my turbos I forgot to attach one of the lines and although running great, ZERO boost. Exhaust note did also change a bit.

[mr.bangle3]

Originally Posted by david in germany

First check the easy stuff, vacuum lines. Start at the vacuum canisters and work your way to the other side of the engine. No vacuum = no boost. If you haven't done it yet, upgrade all of the lines to silicone lines.
By the way, the reason I said this is when I swapped out my turbos I forgot to attach one of the lines and although running great, ZERO boost. Exhaust note did also change a bit.

Originally Posted by david in germany

First check the easy stuff, vacuum lines. Start at the vacuum canisters and work your way to the other side of the engine. No vacuum = no boost. If you haven't done it yet, upgrade all of the lines to silicone lines.
By the way, the reason I said this is when I swapped out my turbos I forgot to attach one of the lines and although running great, ZERO boost. Exhaust note did also change a bit.

I'll go back over them again but almost positive they're all good. any ideas on the smoke?

[Serf27]

Valve seals/guides could be the cause of smoke after the car sits for a while.
Turbo seals could also be an issue and burning oil. But the turbo seals would cause smoke even when warmed up, mainly at idle.

I agree, change the vacuum lines or at least inspect them.

[david in germany]

Originally Posted by Serf27

Valve seals/guides could be the cause of smoke after the car sits for a while.
Turbo seals could also be an issue and burning oil. But the turbo seals would cause smoke even when warmed up, mainly at idle.

I agree, change the vacuum lines or at least inspect them.

Yep!