WHATS A POP-OFF VALVE?
Oil filters don’t just filter particulates out of oil, they also have a pop-off valve. What does the pop-of valve do? If the filter becomes plugged with debris, to the extent that no oil will flow through it, the engine will blow up. The pop-off valve insures that oil keeps flowing to the vital parts. It is a safety valve that allows oil to bypass a clogged filter when the oil pressure goes up. Filters don’t need a pop-off valve if the manufacturer designed one into the engine case. It is basically a ball and spring affair.
