I was driving home the other day, and my oil pressure gauge dropped to 0 and the dash light came on telling me to check gauges. I recently changed the oil, 10W-30, and a new WIX filter. The oil, aside from being very dark, had no coolant in it at the time of change. The sending unit is also newer, as I had to replace it. I have a mechanical gauge on it's way, should be able to check that on Monday (1/22/2018).

I have searched and searched but most people's issue arises with low pressure after warm up, and a change in pressure at various RPMs. Mine is a constant 0. Before it dropped, it would read a constant 15, no matter the idle.

My question is, what should I look for before dumping money into a new oil pump, or sending unit, things like that?

 

Some people have fixed the issue by removing the sending unit elbow and cleaning the port into the block with a pipe cleaner. Your pressure was constant 15 at idle or at any rpm?

 

I cleaned the brass fitting on the sending unit, no change. Does the port into the block also come off? It was a constant 15 at any rpm.

 

Reading the pressure with the mechanical gauge will answer that for certain. If it reads low on the mechanical gauge, you know you have a mechanical problem that needs to be fixed. If it reads normal, you know you have a problem reading the pressure, which will be electrical or an obstructed passage to the sender.

Based on what you have written so far, it sounds likely you have a problem with the sending unit, wiring or gauge. It would be extremely unlikely to have an actual pressure of 15 psi all the time regardless of RPM. And now that it's reading zero all the time, if you really had zero oil pressure, you'd hear it as the engine clattered and chattered. Basically, you'd know.

I'd do what Cherojakee said and clean out the passage to be sure, but I would also inspect the wires going into the sending unit connector to make sure none of them are chafed or broken. Then I'd try replacing the sending unit with a real Mopar sender. If that doesn't help, start looking at the wiring up to the gauge and the gauge itself. Gauges don't go bad that often, but occasionally they do. It's usually the sender or the wiring.

 

The port on the block is on the block, so if you got the sensor off that's sufficient to take a pipe cleaner and gently run it into the port and make sure it's clear. The mechanical test gauge will plug into that port.

You are looking for the mechanical gauge to read 13psi or higher at idle and up to 60 or so when the engine rpm is high. Colder Temps will cause the pressure to be higher, so if you first start it cold it could read 40-50psi at idle - this is ok. It should not drop below 13psi at any point.

As mentioned, the Mopar sending unit (sensor) is preferred. However I have had good luck with the BSD brand (Advance and Pep boys carries this one) and it's only about $30.

Good luck and don't forget to report back with your results.

 

I appreciate the input! I will test readings and clean ports and then for sure let yall know what I find.

 

Mechanical guage finally came in two days late (probably the snow). Got.it hooked up and it read around 40-45 on startup, increased with rpms, around 60 at 4000. So that rules out oil pump then? And just an electrical malfunction. I'll be ordering a Mopar sending unit, and also inspecting wires to the guage.

 

Actual oil pressure sounds perfect. The new sending unit (connected with good wiring) should fix your issue.

 

You have to wait til it’s fully warmed up and use that reading for the oil pressure. And by fully warmed up I mean bring it up to operating temp and then idle for another 10-15 minutes then take reading. The oil takes a while to warm up and is more thin and viscous when it does, so it affects the pressure. That is normal.