Is there a way to check if the PCV valves are working correctly.


What is the difference bewteen the PCV valves on the valve covers and the crankcase breather tube on the front of the engine?


If the PCV valves allow the crankcase to ventilate, then what does the crankcase breather tube do?


Thanks in advance.

Sorry, my truck doesn't have any.


But the way I use to check them on gasser cars was to pull them off, shake them to make sure the ball check valve is not stuck, (it will rattle), as wash in gas or buy a new one.


The crankcase breather tube allows the crankcase to breathe. PCV valves came along for emissions purposes. before most of use were old. There were no PCV valves, just a funky valve cover plug that doubled as an oil fill cap.

These don't pull off and they don't rattle. thanks anyway.