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Hello Brickboard, it's been a long time since I've posted here but I do read the board from time-to-time. I know there is about 10000 years worth of experience here and I need some education.
I have a B18 that has massive blow-by but I don't understand the symptoms.
If I understand engine breathing correctly, the front filter is a fresh air source for the crankcase. The oil trap allows most of the oil to condense out and drip back into the crankcase. The pressure differential should "pull" from the front filter, through the oil filler cap, into the crankcase, past the oil trap, PCV valve, and finally into the intake. I know that blowby is increasing the crankcase pressure but I don't understand the path of the pressure. If I disconnect the hose to the front filter, oil pushes past the seal around the base of the filler cap. With the throttle valves closed at idle or overrun, the vaccuum in the intake system should pull all the vapors. During acceleration the pressure would build in the crankcase but the intake tract is still a lower pressure point relative to the atmosphere. The car does not send oil smoke out the tail pipe; only oil vapor condensing in the front filter and dripping all over the place making a huge mess. I've checked the oil trap, hose, and PCV. They are all clear. Why wouldn't the blowby take the lower pressure route into the intake, past the valves, and out the tailpipe?
BTW, this is a replacement engine installed by the previous owner. I've had it for three years. It has always pushed oil but it is getting worse. The original engine is in the shop now being evaluated for rebuild.
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Mr. Shannon DeWolfe -- (I've taken to using Mr. because my name tends to mislead folks on the WWW. I am a 49 year old fat man ;-) -- KD5QBL
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