A side effect of crankcase ventilation, in which the vented gases entrain some of the engine oil, is to the benefit of the engine. These oil droplets are used to lubricate the intake valve seat rings, increasing their life. To prevent the gases from carrying away a large amount of oil with them, a pressure reducing valve is located on the crankcase vent on the cylinder head cover.
Attention! A drop in compression with a simultaneous increase in the volume of gases removed from the crankcase indicates wear on the pistons, piston rings and working surfaces of the cylinders.
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