what would cause the oil pressure to drop very low when the engine idles running on 1997 Ford F-150

its has around 40lbs at idle 2 or 3 lbs the engine has 125000 mile on it very will takin care of

by in Council Bluffs, IA on December 28, 2012
2 answers 5 comments
ANSWER by , December 28, 2012
More info. on truck 97 F-150 aint enough! 5 engine possibilities, oil sae, what brand of filter. Is this a new problem? Are you checking it with an actual test gauge?
COMMENT by , December 29, 2012
Sorry its a 4.2 V6 Tried Changing the Filter and Oil I Use a 10/30 Quakerstate
COMMENT by , December 29, 2012
That's ok noboy gives enough info. How are you testing the pressure?
COMMENT by , December 29, 2012
remove the sending unit and installed a manual gauge sound like I can hear a knock like main bearings?
ANSWER by , December 29, 2012
I agree with wetry its hard enough to figure out problems if we dont have enough info
COMMENT by , December 29, 2012
Thanks GG.
COMMENT by , December 30, 2012
if you have knock then your oil pump might be gone you should get it checked before the engine blows