Glossary “crankcase fumes” Definition:
Vapors inside the crankcase that could contaminate the air, including unburned fuel vapors, water vapor, or blow-by gases. Also known as crankcase vapors.

Glossary “crankcase pressure” Definition:
The pressure produced in the crankcase from blow-by gases.

Glossary “crankcase scavenging” Definition:
The process by where fresh air is mixed with blow-by gases in the crankcase so that the bow-by can be efficiently removed through the PCV system. This is important because blow-by gases can dilute the oil if not removed.

Glossary “crankcase vapors” Definition:
Vapors inside the crankcase, caused by blow-by, that could contaminate the air, including unburned fuel vapors, water vapor, or blow-by gases. Also known as crankcase fumes.

Glossary “crankcase breather” Definition:
A tube or vent that allows excessive crankcase pressure to escape.

Glossary “crankcase dilution” Definition:
Thinning of oil in the crankcase, caused by the condensation of fuel, due to blow-by, and by seepage past the piston rings.

Glossary “crankcase emissions” Definition:
Vapors that leave the crankcase by way of an open or closed ventilation system.