Quote Originally Posted by 76GMC1500
What pressure does the oil filter bypass valve lift at? I've been meaning to ask and don't feel like starting a new thread for it.
the bypass pressure is dif. on each filter brand, it runs from 15 to 25 lbs. on most cars, but its not the free flowing oil pressure from the pump that makes it work, its how restricked the filter is or how backed up the oil gets from dirt or thick oil.
Most engines incorporate a bypass valve across the inlet and outlet of the full flow oil filter within the lube oil system. The valve is designed to open and bypass oil around the filter and/or element when the restriction reaches its opening pressure
The bypass flow circuit ensures oil flow to the engine when there is a significant restriction across the filter due to element plugging or cold start conditions. Typically, engine manufacturers design bypass valves to open at a pressure differential of approximately 10 to 30 psid with some as low as 4 psid and others opening as high as 75 psid.