porath1969

i was going to replace the valve seals on my 97 f-150 4.2 engine and just for giggles i decided to do a compression check all were at 160-170 except the center cylinder on the drivers side that one only had 30 lbs of pressure i checked it 5 times with the same result... what can i do to fix this besides a complete rebuild ... did a blow by test at the pcv valve and there is no blow by..