Causes. Plugged breather valve Excessive ring blowby. Blown head gasket passing gasses into crankcase. Cracked piston.
Only X amount of ways to pressurize the crankcase.
What do you think would be the leakdown values for a cylinder with excessive blow-by to create crankcase pressure? 100% perfect, what is the leakdown magnitude (%) for 'not good'? I've gotten different answers for this question before so i'm just trying to see where the average 'no good' value falls?