engine and drivetrain White smoke after sharp turns

[sazan]

Hi guys,

 

I am trying to diagnose my engine issue here. Recently my car started spewing white smoke when I go over a bump, make sharp turns going faster than 20 Mph and when I need to brake hard to stop then get going again. It does not smoke when running straight. 

 

I checked the oil cap and level. There is no sign of white oil due to oil and water mix. 

 

Is this a sign of leaking head-gasket? Could there be a leak with the exhaust system?

 

Thank you for your kind suggestions in advance. 

[Mike Self]

Is what you're seeing really "smoke" or is it vapor?  

 

If the former, it's possible that you have a master cylinder that's leaking brake fluid into your brake booster; when you corner, some of it gets sloshed into the vacuum hose that connects the booster with the intake manifold, where engine vacuum draws it into the engine, where it's burned and emerges as white smoke.  

 

If the smoke is more grey, you may have overfilled the engine with oil and it's sloshing around to be sucked into the combustion chambers--that could also be worn valve stems or stem seals, but that usually occurs on trailing throttle, especially at high rpms.

 

From the symptoms you describe, I'd check my brake fluid reservoir to see if the level is dropping, then check inside the booster vacuum hose for evidence of brake fluid in the hose.

 

Let us know whatcha find--an intriguing problem.

 

mike

[sazan]

Hi Mike, 

 

Your answer regarding the brake fluid leak makes complete sense. The smoke is white and it does smoke from the engine area as well as the exhaust.

 

My mechanic had suggested to replace the master cylinder but never advised me about this symptom and obviously I had no idea.

 

I had to refill the brake reservoir this morning and was thinking about replacing master cylinder and overhauling front and back brakes. 

 

Now need to find a seller for these parts!

 

Thank you for putting my mind in ease regarding the engine and your quick response.

 

Sazan

[Mike Self]

Try Blunt Tech (Steve Peterson) on this board for parts.  Gen U ine BMW parts, good prices, and he'll make sure you get all the pieces you need for a successful fix.

 

For proprietary parts (those not made by BMW) you might also try Autohaus Arizona (brake pads other than the factory ones--lots of better brands than what BMW sells), master cylinders, wheel cylinders, calipers etc.

 

mike

[Stevenc22]

Make sure the fluid hasn't damaged the brake booster which is a expensive and hard to find replacement part. At he very least clean and drain and brake fluid from the booster when you replace the master.

[dang]

Yep, I had a coupe do this exact thing.  I scared a lot of people at the gas station when I drove over the bumpy fuel tanks in the ground and it started pumping out smoke EVERYWHERE!  I filled the entire station under the overhang.  It doesn't really have much of a smell though so I knew it wasn't engine oil.  I disconnected the vacuum line to the booster and by the time I made the five minute drive home the smoke was gone.  Replaced the master cylinder and all was good.