Description
Forced crankcase ventilation system (PCV — Positive Crankcase Ventilation) designed to return to the intake manifold gases that have broken through from the cylinders into the crankcase.
Gases are supplied to the intake manifold through a valve with a flow area sufficient to pass during normal engine operation as burst gases. as well as air entering the crankcase. Air enters the crankcase from the air duct through the PCV filter under the action of a small vacuum formed during the suction of gases.
At a wide open throttle, the vacuum in the intake manifold is not enough to suck the career gases through the valve. Overpressure builds up in the crankcase, the supply of fresh air stops and the gases pass through the cylinder head cover and filter into the throttle pipe.
In cars with a worn-out cylinder-piston group, the breakthrough of gases is greatly increased and their complete suction through the valve is impossible. Part of the gas flow constantly passes through the cylinder head cover and filter.
The figure refers to GA14DH/16DE engines for Europe and GA15DE. In other engines, the system is fundamentally arranged in the same way. The SR engine does not have a filter.
Examination
PCV valve. With the engine idling, remove the valve from the cylinder head cover. A normally functioning valve should make a hissing sound. When closing the valve opening with a finger, a strong vacuum should be felt.
PCV hoses. Check hoses and connections for leaks. Remove the hoses and blow them out with compressed air. If the hose cannot be removed, replace it.