Smoky air intake system and oil in the intake system in BMW – how to fix it?

BMW driver question

Is it normal that smoke is coming out of the air purge line in large quantities? My car has almost 300,000 km on the odometer, it doesn’t take oil, the turbo seems to be passing a little. I use Castrol 5W30 oil. Below is a video of the symptoms that concern me.

The problem was on a 2007 BMW E91 318d with the M47 engine, but it can happen on other models as well.

Response from BM Cars service

The air purge valve located on the hoses from the crankcase vent is designed to let the gases coming out of the crankcase pass through, and at the same time stop residual oil trying to get into the intake manifold along with the exhaust. The kind of smoke you see in the video is perfectly normal.

The important thing is that the oil does not get into the intake system. If there are significant amounts of oil in the intake manifold and intake system (air ducts, intercooler and intake manifold), it is necessary to find the cause and clean the system.

Oil can be passed through a faulty air purge or through the turbocharger. If oil is pumped from the turbo along with the air, the engine risks running out. The engine will be fed its own oil. It is then necessary to repair/repair the turbocharger or replace it.

We invite you to visit our service center to accurately diagnose the situation.

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