Originally Posted by spankyfarly
I have a 94 ram 2500 with the 5.9l 360. On the highway I noticed my oil pressure gauge showed almost 0psi. Every time I let off of the gas pedal it would go back to 40. As soon as I accelerate it goes back to around 0 again. I pulled over and at idle its at 40 again.
Oil level was good I checked it before my trip.
I didn't notice any strange knocking or pinging.
After getting back on the highway it did the same thing it seams like the higher the gear I was in the lower the pressure gauge read. After about 15 minutes or so it went back up to 40 and stayed there for the rest of the trip. The next day for the return trip it did every thing it did the day before.
Any Ideas what this could be.
Well could be many things, it could be a faulty sending unit which is likely because it's an electronic sensor and well a vehicle that old... It could also be the pump it self or the release valve is broken in the pump but I doubt this. Another thing it could be is sludge formation at the bottom of the oil pan, sometimes sludge forms where the pump screen is and when this occurs you get readings much like yours lol had a friend same thing it was sludge because of a coolant leak, but sludge forms over time with or without water depends how often you change your oil and maintain the engine.