Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Crankcase Ventilation Systems: Description
The crankcase ventilation system for Audi vehicles consists of a rubber hose containing a metered orifice. Some models may contain an in-line PCV valve instead of a restricted orifice. The hose is connected to cylinder head cover at one end and the air cleaner at the other end. The system is sealed and prevents crankcase vapors from reaching the atmosphere by drawing them through the hose and into the air cleaner.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.