i was driving my 2000 ranger 4.0 4x4 last sunday, it was kind of warm out so i turned the ac on for the first time since last summer/fall. a few miles later i came to a stop light and my oil pressure gauge started fluttering from high to low and back and the check gauge light came on. as soon as the light turned green and i gave it gas it went back to the normal 1/2 way point. i pulled over and i was leaking coolant, a moderate drip, from the water pump area. oil level was ok but the coolant was a little low so i topped it off and went home. for the last week ive driven it a few times with no more issues until today when the oil pressure started fluttering again. i am due for an oil change but am having trouble figuring what could be goin on. any thoughts?

 

OIl presure is most likely the sending unit. Sounds like you need a water pump too for the coolant leak.

 

water pumped just leaked the one day, then it stopped leaking. not sure what happened. i flushed it and its been fine since. the oil pressure sensor was causing the flutter. got a new sensor and its been fine since as well.