Audi 80 Quiz
Engines

Crankcase Ventilation

In this manual: Engines
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~1min read

Even a serviceable engine forces 50–70 L of combustion gases per minute past the piston rings into the crankcase. This pressure must be released from the crankcase so that the sealing gaskets are not overloaded. This is done by crankcase ventilation. To protect the environment, the toxic gases from inside the engine are returned to the intake passages or to the air filter housing. From there they are drawn into the engine once more for complete combustion.

Note: if the crankcase ventilation emits a noticeable smell of oil, this indicates significant wear of the pistons and cylinders.

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A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.