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AV-SCANNER / Service function guides / Engine and oil
This guide covers the complete process of testing and servicing a positive crankcase ventilation (PCV) system, from understanding its operation to curing oil consumption and related driveability faults. It is written for motorists who maintain their own vehicles and for working mechanics who need a structured, repeatable procedure across many makes. You will learn how to measure crankcase pressure and vacuum, inspect and replace PCV valves, hoses, and separators, and verify that the repair has actually solved the underlying problem. After finishing, you will be able to diagnose a failed PCV system with confidence and perform a service that restores proper crankcase ventilation.
Guidance is general and covers many makes. Exact procedures and values vary by model, so confirm them in the factory service information for your vehicle.
Download all 11 sections as a branded PDF to use in the workshop.
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