I'm sure this has already been a topic on this forum. But I wondering if anyone has experienced a ping from corollas with high mileage. We have this issue on an '01 for 266,000 kilometers. Is this a PCV valve?
'01 toyota corolla LE question
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I have high miles, but I don't ping. The PCV valve is a simple ball check valve. It is oriented so that vapor flows from the cam/valve cover to the vacuum source, usually the intake manifold or tract. It has two failure modes, stuck open and stuck closed. Stuck open would allow normal flow of crankcase oil vapor to the vacuum source, but would allow intake pressure pulses to flow back into the cam/valve cover. This could allow gasoline into the engine cases. Gasoline has almost no lubricating properties for high-pressure applications such as crank bearings and cam followers.
Stuck closed causes a slight power loss. The PCV valve has one major function and one minor side-benefit: it allows crankcase oil vapor to be burned instead of venting to atmosphere and the vacuum applied to the crankcase reduces crankcase pressure slightly. Pistons moving up-and-down pump crankcase air as wells as intake air, using horsepower to do so. Reducing the crankcase pressure reduces pumping losses.
Your pinging has nothing to due with the PCV; if it's gunked up and not rattling, that's an indication of badly worn rings and valve guides.
If you know there have been topics on this, then why start a new one???:disappoin
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