I drive a 2000 Nissan frontier and there is air blow by out of the oil cap is that a problem?
Yes, that is a problem. The rings are worn if a lot of blowby comes out the oil cap.
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Excessive crankcase blow-by. Check your PCV system. And maybe run compression test as you rings are likely shot.
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Install an oil cap, the vapors will be controlled by the positive crankcase ventilation system.
Some engines, even when functioning properly will have a lot of “air” blowing out of the oil cap, and if you remove the oil cap while running, it will even make a lot of noise. I wouldn’t make the diagnosis of excess blow-by/worn piston rings based solely upon how much “air” (combustion gases) you feel blowing out of the oil cap when opened.
Really? I’m curious, where is this “a lot” of air coming from, in a normally functioning, modern engine?
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Excessive blow-by is caused by worn cylinder walls/rings in the engine, or the PCV system is restricted.
For a worn engine, this product may reduce the blow-by.
Tester