when truck really heats up, after 1 hr highway driving, come off highway, have to stop, when truck comes to complete stop, idle drops, oil pressure gage fluctuates, bringing idle up, gage comes up also. happens after that everytime i stop, runs ok when in motion. went through big puddle when having problems, all problems stopped. mechanic shop could not duplicate problem, ran all day. did replace sending unit, and said oil pump is working.
work is the 1 hr highway drive, really need some help. been told electical problem--good luck. been told sump(?) problem. anybody fix this problem?
don't have money to throw at problem.

 

If the problem stopped after the puddle, it's possible the connections are the problem at the sending unit. It could be cooincidental too. Have you tried spraying water under it to see if it changes What engine is it?

 

4.2 6 cyl

 

If it was a puddle, I'd really believe it has to be a connection problem. Did they put a mechanical gauge on to check the oil pressure?

 

mechanic put manual gauge on engine, ran all day at shop, oil pump is working.
wondering if am chasing ghosts, maybe is just stalling problem, just that the oil pressure gauge is the only thing I see moving, the other gauges are not moving.

 

If your idles dropping, then your pressure is gonna drop. I'd look into why your idle's surging like that, you fix that then your oil pressure should be fixed too...

 

True but unfotunately the oil pressure gauge in later model F150's is nothing but a glorified light and is either normal or not as it is either "on" or "off".
So I ask this question of Ford, HOW MUCH MORE WOULD IT HAVE COST TO PUT A REAL OIL PRESSURE GAUGE IN THE THING?????????

 

Very good question, I never realized that one...

 

I had the same problem in my truck for awhile. I changed sending unit and oil pump and it still did. What type of oil filter do you use? I was told to switch to motorcraft and use a heavier weight oil. When I did this the problem stopped. Unfortunately a lot of damage had already happened to the engine and I had to have it replaced but that was a few thousand miles after the oil pressure problem had stopped