I have a 1996 2500 V10 4wd the oil pressure gauge started twitching and oil pressure below 40 probably around 25 probably. A couple times it shot down to zero and the light came on but as soon as I would give it gas I would go back up never to 40 though. I changed the pressure sending unit, no change. In fact it's worse, shoots down to zero a few times a day. Never when it's first started in the morning, usually it's after I have been driving a while then stop, when I get back in and start it it will zero out and the light will come on. I hooked up an analog gauge and reading very low about 15 or so, I can get it to go to 25 max and that's only hitting the gas while driving. Dropped the oil pan, pickup tube and screen is clear, pan clean as a whistle. Oil pump probably?

 

Could be. Unfortunately, the oil pump is in the timing cover, so, kind of a drag to get to. You can replace the rotors, they are still available, but, you can't do much about the cover if it is scored, or otherwise damaged. There have also been reports of the screws holding it all together backing out.... Don't know if you can see that without tearing it down though......

So, it may be a simple fix, or, it may require replacement of the timing cover, and oil pump gears....... Not really a bad job all things considered.... just, expensive. The cover itself is fun to find, and I think the cheapest I have seen a 'new' one, is around 400 bucks..... You could gamble on a used one, but, might end up with something worse that what you already have. They are not repairable...... (aluminum, after all....)

But, you won't know what ya got, until you tear it down, and look. Fixing it NOW, before low oil pressure toasts the motor, is a very good idea.

 

If I was going to replace the rotors would I not do the pump anyway since I was already in there?

 

There is no 'pump' per se. Just the rotors riding in a machined cavity in the timing cover, with a metal plate over it to hold everything in place. The rotors are pretty much the only replaceable parts..... aside from the timing cover itself. Its not like on the V-8's, where you just remove one bolt, and the pump falls off into your hands.

 

shows what I know. I'm no mechanic that's for sure. Just a book some tools and my driveway, oh and this forum. What would you suggest I get before tearing into this?
Rotors, timing cover gasket set, crank case seal, locktite, shaft repair sleeve just in case (I think theirs such a thing?), oil change supplies. Where have you seen the timing cover for sale at? The way things are going with this truck I'm gonna need one.

 

Think I would replace the water pump, and main radiator hoses as well, they gotta come off anyway......

Finding the cover is really random.... A boatload of sites list it, but, unfortunately, most of them show it as discontinued. Not really helpful. Check out some of the mopar parts sites, find the part number, and then do a google search on that, find one that is reasonably priced. You *may* get lucky on a used one, but, that is up to you if you want to go that route.

Skip the 'repair sleeve' for the balancer, its really rare that it is actually needed, and I have never had much success installing the sleeve, they always wrinkle on me, and that just won't work.

Definitely an oil change.

Some blue lok-tite for the oil pump cover screws as well. You do NOT want them fellers backing out.

Before you tear into it though, check the pressure relief spring, they like to break, and your oil pressure does weird things.

You can download a service manual for your truck from here. Read thru the procedure for the oil pump a couple times, and if you have any questions, ASK!

 

I replaced the crankshaft seal about a month ago and the harmonic balancer was grooved pretty good, I was able to install the repair sleeve. I thought there was some sort of repair sleeve for the timing cover. Thing still leaks though, just not near as bad. Forgive my ignorance but where is the pressure relief spring located?-----Ok, found some info online, pressure relief valve on the timing cover housing above the oil filter or possibly on the other side? Just unscrew it check it, clean and reinstall if not broken?

 

Correct on the spring.

Just replace the balancer, and use the stock style seal. Much more likely for it to actually work that way. However, I have also hear of 'offset' seals, that put the lip that actually does the sealing in a different spot, might wanna see if you could find one of those.... although, if the sleeve on the balancer isn't PERFECT, it will never seal.

No repair sleeve for the cover/oil pump that I have ever seen. And even if there was, I sure wouldn't trust it. Timing cover is a few hundred bucks, new motor is MUCH more expensive.

 

UPDATE: I checked the relief spring, it's fine. I did notice that the plug came out very easy. When I reinstalled the plug it seated much farther in than it was, it was loose. When I started up my truck the gauge seemed to show pressure quicker and pressure seemed more stable maybe even a little higher. I shut it off then back on again 2 or 3 times, no gauge drop or oil pressure light. I took it for a test drive and pressure seemed a little more stable, it never got above 40psi, stayed a little below at max. Thought I had it, but then I pulled into my driveway shut it off, turned it back on, gauge built pressure then needle slammed back to zero and oil light came on. Give it gas and light goes off and needle goes up, let off of gas and needle slams back down to zero and light comes on. Shut off and restart a few more times with same results.

 

Check it with a mechanical gauge. If you get the same results, time to tear into it. If the mechanical gauge shows it has good pressure, and will maintain it, replace the sending unit. (again......)