<TABLE><TBODY><TR><TD vAlign=top width="100%">i have a 97 f150 with a 120,000 miles on it. when the truck warms up and sitting at a stop with the brake on i start to loose oil pressure, but when i touch the gas or shift into park it goes right back up, and is soild as a rock. i changed the oil pump and relieve valve.
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Have you checked the sending unit to make sure it's reading right? Everything else is ok? I would focus on the sending unit and the gauge itself.

 

Well unless you modified something the oil pressure gauge is just an idiot light. Something like 7 psi it reads dead center, below nothing. I’d check the wiring on the sender.

 

I'd check the actual pressure with a real gauge to see what is going on.

 

well i replaced the sending unit, well according to the gauge and the light it got worse. the gauge still bounces around and after it gets real hot, unless i gave it gas it drops like a stone even in park. any help would be great.

 

What LxMan said.

 

hooked up a gauge and started at 60 psi untill it warmed up the droped down to 20psi and bounced and around and slowly went down
any help?