Volkswagen Front Wheel Drive 1974-1989 Repair Guide

Crankcase Ventilation System


See Figures 1 and 2


The purpose of the crankcase ventilation system is two-fold. It keeps harmful vapor by-products of combustion from escaping into the atmosphere and prevents the building of crankcase pressure which in turn causes gasket failure and oil leaks. Crankcase vapors are recirculated from the camshaft cover through a hose to the air cleaner. Here they are mixed with the air/fuel mixture and burned in the combustion chamber.

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Fig. Fig. 1: The crankcase ventilation hoses should be removed and checked for clogging at every tune-up


The crankcase ventilation system should be inspected at the interval suggested in General Information And Maintenance . Remove the crankcase ventilation valve (if so equipped) and examine both the valve and hoses and for clogging or deterioration. Replace any components as necessary.


To remove the Positive Crankcase Ventilation (PCV) or crankcase emission control valve, simply pull it out of the camshaft cover and its hose. On models not equipped with these valves, remove the PCV hoses by twisting and pulling them from their ports. Always check the hoses for clogging, breaks and deterioration.

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Fig. Fig. 2: Crankcase ventilation flow on 8-valve engines equipped with crankcase emission control valves