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Smog Check Repair

Turbocharger and Mass Air Flow Meter Always Covered in Oil?

I have a turbocharged car and the mass air flow meter is or always seems to be covered in oil? What do you think is my issue?


We'd first recommend ensuring the PCV is functioning properly. The combustion process produces many corrosive gases, and on an high compression engine, sometimes oil. The high pressure in the engine cylinder strokes force some of the gases to slip past the piston rings and into the crankcase. To protect your crankcase oil from contamination the PCV system returns these corrosive gases back to the combustion chamber where they are burned alongside the regular fuel and air mixture. A faulty PCV will not be able to return fumes to the intake manifold. A faulty PCV may even allow oil to escape from the crankcase and inadvertently be routed to the intake manifold, turbo or supercharger unit, and/or mass air flow sensor. Ensure the PCV system is functioning correctly.

If after having inspected the PCV, you find the system functioning properly (PCV not stuck open), we'd recommend inspecting the supercharger seals.

Without having diagnosed the vehicle first hand, it'd be difficult to say where the problem lies, but since your mention both the MAF and supercharge have an oil leakage issue, we'd lean more towards a faulty PCV system.

posted by SmogTips Support 02-12-2019 01:41 PM
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