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 on 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 on December 29, 2012
Sorry its a 4.2 V6 Tried Changing the Filter and Oil I Use a 10/30 Quakerstate
COMMENT by on December 29, 2012
That's ok noboy gives enough info. How are you testing the pressure?
COMMENT by on December 29, 2012
remove the sending unit and installed a manual gauge sound like I can hear a knock like main bearings?
ANSWER by on December 29, 2012
I agree with wetry its hard enough to figure out problems if we dont have enough info
COMMENT by on December 29, 2012
Thanks GG.
COMMENT by on December 30, 2012
if you have knock then your oil pump might be gone you should get it checked before the engine blows