I have a 94 ram 2500 with the 5.9l V8. 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 put my foot on the pedal to maintain speed 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 and during 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.
I only had this truck for a month now and this is really the first time I had it on the highway.Normal around town driving the pressure gauge seems to stay at 40 all the time.

Any Ideas what this could be.
Thanks

 

Welcome to Dodge Forum 2nd gen area!

This is a common thing with these trucks, First is to get a mechanical gauge and test to see just what psi you have, Second if that shows good then replace the oil pressure sending unit with a mopar part if you wish to. Personally I have replaced so many of these sending units I have gone to a permanent mech gauge. If the mech gauge shows min oil psi then time to drop the oil pan and replace the oil pump about 2hrs work.
Of course this is based on that your mains and other bearings are in good shape.

 

alright well if the oil level is good. then its either 2 things. the sending unit, which is cheap and takes like 10 min to change. its on the back of the engine right next to the distributor.

Or its the actual dash cluster gauge. mine was the cluster, and i know this because i installed a mechanical oil pressure gauge.

 

Thanks for the replies. I plan on checking the oil pressure with another gauge.
I only had the truck for about a month now, and this is the first Dodge I ever owned. It only has 82000 miles on it.
From reading on the forum here I noticed there is a problem with the plenum gasket on these,Could this be a symptom of that?
I haven't had the truck long enough yet to see if it consumes more oil then it should, I will have to wait and see.

 

I was talking to a mechanic friend and he said he's worked on two 01 dodge rams (not sure if 94 suffers as well) that have these little screens in the oil pan that when heated up on the highway will cause the carbon to clog the screen. He said it's a huge problem if ignored too long and it causes the oil pressure to drOp