Review on PH3980 Extra Guard Passenger Filter by Charley Martinez

Many may not realize that not all oil filters are created equal. Some aftermarket oil filters are made from really cheap filter materials and may not even have a check valve inside. Fram truly have the best oil and air filters available today as they have both high quality filtration and working flow check valves. I have a 1998 Blazer 4x4 and the local transmission shop removed the oil pan and installed a cheap nameless aftermarket filter when it was done, resulting in an issue with valve rattle and transient low oil pressure during startup. The problem was that the flow check valve in the oil filter was not working, causing the filter to empty after parking with the engine off. (Blazer 4x4 oil filter is in horizontal position) Every time I restarted the engine it rattled until oil pressure was restored. Replacing that junk with a new Fram oil filter solved the oil pressure problem on startup and completely eliminated the noise and oil pressure problem. I also found Castrol 20/50 at Revain and applied them at the same time.