Oceanside Auto Repair

Why does my BMW smoke when I start it?

Why does my BMW smoke when I start it?

Have you noticed smoke in your BMW when starting up? Maybe you've recently bought your BMW and aren't quite sure how to take care of the car. Or maybe you're an experienced owner who has more questions coming to mind, but not wanting to pay for an expensive mechanic.

Here at Oceanside Motorsports, we can find out what’s wrong with our diagnostic testing to ensure you’re only spending money on what needs to be fixed.

Possible reasons why your BMW smoke during startups

Faulty Crankcase Vent Valve (CCV)

A gasoline vapor recycler, the crankcase vent valve or CCV is located beneath the hood of your car. The main purpose of the crankcase vent valve is to reuse blow-by gases by recycling them back into the crankcase and protecting your BMW's engine in the process. When you notice a white smoke coming out of the exhaust during startups, a faulty CCV could be the reason behind this.

Blocked Positive Crankcase Ventilation Valve (PCV)

The exhaust pipe may emit black or white smoke because of a malfunctioning PCV valve. A clogged PCV valve could push oil into the combustion chambers of your BMW, causing oil to burn there and escape through the exhaust pipe. You might see a lot of blue smoke coming out of the exhaust pipe.

Bad Valve Stem Seals

Poor valve stem seals are the cause of your BMW's smoke. Excess oil entering the combustion chamber and burning up will come from a problem with a valve seal or piston oil ring, increasing oil consumption and spewing a ton of foul blue-white smoke from your exhaust. Over time, worn-out valve stem seals harden and cease to function as a suitable seal between the stem and the seal, causing oil to flow into the exhaust and combustion chamber.

For over 12 years, Oceanside Motorsports has been an Oceanside staple helping you get back on the road faster than the dealer can. We have continuously trained technicians and offer a lifetime warranty on most repairs. With our Time Saver Service, we can get your car and deliver it to your doorstep once fixed. We can even help arrange to tow if needed. You can also have our free loaner car while your car is serviced! You'll get used to expecting quick, simple, and dependable auto repairs from Oceanside Motorsports!


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343 Airport Rd. Oceanside, CA 92058 (760) 721-5500