I have a 95 dodge 3/4 ton diesel 2wd automatic. I have a recent problem with oil pressure. It is fine until it has warmed up, the oil pressure light will come on when the RPM gets below 1000, and if I get below 30mph the actual gauge will immediately drop to 0 pressure until I get going again and it goes above 1000rpm. The temp, exhaust temp, and manifold pressure all read normal the entire time this is going on. And it doesn't always do this, sometimes it just stays normal. The only thing I can think is the pump is going out. Any advice?

 

I would have to say that your oil sending unit is bad.

 

Thanks, what is the best way to test it?

 

Check the pressure with a manual guage. If it is steady and above 10 or so at an idle, replace the sender.

 

Thanks, will do.