6.9 Diesel Oil Pressure Problem

[Neil Wig]

I've been experiencing an intermittent oil pressure loss on my 6.9 L Ford Diesel. If I drive the truck when the engine isn't fully warmed up, the oil pressure drops as the truck warms up. When the truck is fully warmed up, and I hit a bump, the oil pressure jumps back up to where it's supposed to be. This sometimes happens without hitting a bump.
I've been pretty sure it was an oil pressure regulator problem since it started happening, but today I finally received some confirmation.
The oil pressure regulator is located behind a little hex plug just above the oil filter. Behind that plug I think there is a spring loaded punger or plug. The spring is being compressed due to high oil pressure when the engine is cold. The plug is sticking in the bore, not returning to its closed position. This is allowing oil to bypass back to the oil pan when the engine warms up, causing low oil pressure.
Has anyone else experienced this problem?
Does anyone know what size hex is in the oil pressure regulator plug?
Can anyone tell me if I'm correct in assuming there is a spring loaded plunger behind the threaded plug?

Thanks Much.

Neil

 

[Highbeam]

Sounds like the gauge or the wiring to the gauge. It is cheap and free to make sure the wires are connected firmly. Oil pressure is important, you may want to look into a mechanical oil pressure gauge to temporarily install so that you can really watch what is going on. These are cheap.

 

[Neil Wig]

Thanks for the reply Highbeam.
I was going to put a mechanical gauge in, but it's free to pull the plug and make sure the oil pressure regulator is functioning freely. If I have any doubt, after cleaning the regulator, I'll install a mechanical gauge.

Neil