Skip the auto shop - Our mechanics make house calls

Q: White smoke coming out from exhaust, what can that be?

asked by on

It is a 2010 BMW 550i GT, white smoke coming out exhaust when starting. When driving, hitting gas. Is it head gaskets or CCV valves?

My car has 82 miles.
My car has an automatic transmission.

A: Hello, thanks for writing in. I’d be happy ...

Hello, thanks for writing in. I’d be happy to help.

White smoke from the exhaust can be caused by a few things. First off, keep in mind that white smoke coming from the tailpipe after a cold start can be steam from water condensation in the vehicle’s exhaust system. The steam will usually go away once the car has warmed up. It may also be possible that the issue is related to the head gasket. A bad head gasket can cause smoke from the tailpipe if coolant enters any of the combustion chambers. If this is the case the vehicle may also be overheating. I would check the oil filler cap and dipstick for any signs of coolant contamination that may indicate the possibility of a blown head gasket. If the engine is not overheating then it may be possible that an issue with the CCV/PCV system is causing the smoke. A bad CCV valve can also cause smoke from the tailpipe if any oil from the crankcase gets sucked in by the engine through the PCV system. I would start by trying to figure out if the issue is head gasket related or not, and go from there.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Battery discharging while stopped, electrical devices were temporarily switched off.

The first thing to do with a draw is to check and make sure nothing is on that can be turned on by a human. Some common sources are interior lights, exterior lights, after market stereo systems or other after...

Q: Malfunction sign on dashboard

Hello. There are two basic lights in a vehicle. Red lights typically mean stop the vehicle now or severe damage can occur. These are typically the battery light, temperature light, or the oil pressure light. The other color is amber....

Q: Car turns off at stops

Stalling usually indicates that the engine is not getting enough fuel, or that it is getting too much air. If this happens mostly at idle, I would suspect a vacuum leak, idle air control valve, or problems with the VANOS...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...