Hey guys so here’s my problem:

I have a 1996 Dodge Ram 1500 5.9L Automatic club cab. For the past 6 or 7 months my oil pressure would drop to 0 at idling or a stop light. It would go back up to 40psi the second I hit the gas or if I went into park. A couple of days ago, I was at a gas station and saw a puddle as big as my hand of all oil on the ground. As I was driving it home the oil pressure slowly dropped to 0 even at 3000rpms so I shut it off and got it towed home.

i located the leak to be from the oil pressure sensor, and it was spilling out through the top of the sensor, even through the electrical connections; so my electrical connectors were contaminated with oil.

i replaced the oil, oil pump, pickup tube, and the oil pressure sender unit/sensor which is in the very back of the motor next to the spark plug distributor. The dashboard gauge said I still had 0 pressure even when revved up to 3000rpms, then when I got any higher the needle would finally start to go up to 20.

So I got a mechanical gauge (Maddox brand, harbor freight) that I hooked into the oil pressure sensor hole, and it said I had 0 pressure at idle and barely 10 psi at 3000+ rpm’s. The last rev I gave the truck and got above 3000rpms I heard some lovely little minor, quiet knocks that disappeared when let off the gas. I don’t want to cause any more internal damage so im not turning it back on until I get some help because I haven’t found anyone with my exact situation. Thank you guys!

 

Rebuild time. Running it with low pressure smoked the bearings. You *might* be able to simply replace the bearings, and be good to go.... (and, if it isn't making noise...... that's the direction I would tend toward).... Wouldn't hurt to throw some plastigage on your bearings though, and see what clearances look like at the moment. (to verify the bearings are worn.... visual inspection may be enough....)

 

In the case I get lucky and it’s just the bearings, could I drop the oil pan to access the bearings ? Or am I going to have to pull the motor entirely? I also have not worked inside the motor before, so what bearings are you talking about that I should be researching on how to replace? Thanks again

 

Mine was a 4x4, and it was an exercise, but, I only had to lift the motor a bit to be able to remove the oil pan. All the bearings you are interested in are right there. If you have cam bearing issues, that's a pull the motor exercise.

 

mine is a 4 x 4, too, I was able to drop the pan without lifting the motor to replace the oil pump and pick up tube. I’m glad I’m able to get to the bearings from under the oil pan. What symptoms should I look out for that are cam bearing issues? Thanks again.

 

Pull each main bearing cap and inspect those bearings 1st, as they tend to determine your oil pressure. You can Google what worn main bearings look like, in addition to using Plastic-gauge to check them.

BTW, you can remove the upper main bearing shell by bending a cotter pin into a kinda T-shape, put the long end into the crank oil hole for that bearing and rotate the crank slowly to push out the upper main bearing shell...

 

If you replace bearings, but still have crappy oil pressure..... What else is left.

 

is there anything left? I think you meant this as a joke haha but just want to make sure.

another one of my buddies said to do a compression test and see if my problem could be the piston rings; he said that could explain the reason why the oil was coming out of the top of the pressure sensor

that’s another thing I’m confused about: why is the oil leak coming from the top of the oil pressure sensor if there’s little to no pressure at all? After I put in the new sensor, there was STILL oil leaking through the top and into the electrical connection. Any thoughts? Thank you again!

 

Try re-installing your mechanical oil pressure gauge and see what it may be reading. The current factory style oil pressure sensors are not made very well and are made with plastic parts. You could have picked up a defective oil sensor, too. The sensor on my engine did the same thing...

 

Yeah when I hooked the mechanical oil pressure gauge up through the hole for the pressure sensor, it stayed under 5psi from idling all the way to 2500 rpms . When it hit 3000-3500rpms it finally hit 10psi but I was hearing new small and quiet knock sounds from the motor. Operating range is around 40psi