Blowby is the leakage of combustion gases past the piston rings into the crankcase. This can be caused by:
- Worn or damaged piston rings
- Worn or damaged cylinder walls
- Incorrect piston-to-cylinder clearance
- Excessive cylinder pressure
Incorrect oil level
If the oil level is too high, it can cause the crankshaft to whip the oil into a froth, which can then be sucked into the combustion chambers. This can lead to:
- Engine damage
- Reduced power
- Increased emissions
Clogged oil filter
A clogged oil filter can restrict the flow of oil to the engine, which can cause the oil pressure to drop. This can lead to:
- Engine damage
- Reduced power
- Increased emissions
Defective PCV valve
The PCV valve is a valve that controls the flow of gases from the crankcase to the intake manifold. If the PCV valve is defective, it can cause:
- Excessive blowby
- Increased oil consumption
- Engine damage
