Blow-back is caused by the escape of exhaust gases from inside your engine’s combustion chamber to the crankcase or valve area. When the air-fuel mixture inside the cylinders fires, it creates tremendous pressure that drives the pistons downward.
What causes engine blowby?
During combustion, high pressure on the top side of the piston pushes combustion gasses, as well as droplets of oil and fuel, past the piston rings and into the crankcase. This mixture is known as “blow-by.” Many modern vehicles use complex PCV systems to vent blow-by from the crankcase.
Is blowby bad?
Engine blow-by, smoke and oil use are related issues that, if ignored, can turn into very expensive repairs. Fortunately, in over 80% of cases this can be corrected at low cost, and without any downtime. Typically, blow-by is cylinder pressure leaking past the piston rings into the crankcase.
What are symptoms of bad piston rings?
When drivers notice excessive oil consumption, white or gray exhaust smoke, poor acceleration, and/or overall loss of power or poor engine performance, they may be seeing signs of worn piston rings.
Do catch cans need breathers?
Do not run breathers. Install a catch can and leave the system sealed.
Can a blown head gasket cause blowby?
Registered. Sounds like a head gasket. Worn or broken rings can cause excessive blow by but will not push coolant. You can inspect the cylinder walls when you have the head off.
Do catch cans really work?
The answer is yes. While a catch can won’t stop every last particle of contaminant from entering the intake manifold and coating the valves in a direct-injection engine, the less unwanted buildup the better. … For those who don’t want to empty out a tiny catch can frequently, the larger units are helpful.