So I've read enough to know the stock guages are worthless, and I've probably got nothing to worry about, but...

I want to solve this oil pressure light coming on at idle after a long ride. I could go get a manual guage and plumb it into the cab, and/or, since I've got one sitting around, I could put in a new oil pressure sending unit.

If it's just the sender, I'd be a free, no going to the store solution. But maybe putting in the new sender, and attaching it to the stock guage is a waste of time.

Which would you suggest?
Tys

 

is this in drive at a red light or something, or is it in N or P??? what does it idle at in both??

 

Another question, what oil are you using and have you noticed an unexplained increase of engine oil level?

 

Put the sender in. Mine did the same thing and it was so dang annoying. I changed from 5w-40 to 15w-40 thinking maybe the oil was too thin causing the problem, but it didn't change anything. Put a new sender in almost a year ago and no problems. Although aftermarket is probably more reliable, I like the fact that if I lose oil pressure I get the audible alarm as well as a light on the dash to make me aware of it. If the sender doesn't fix it then you know to look elsewhere. If you have a rising oil level you could have a blown head gasket. Are you losing coolant as well? Not sure about your VE injection pump, but I know my p7100 holds a couple quarts that drains very slowly into the engine at shut down and will show different oil levels when cold versus right after running. Good luck.

Waylan

 

I notice it after a long uphill dirt road, just as I pull in to stop. So, it's still in Drive, and it even blinks a bit, as though there's sloshing going on. It doesn't stay on, but the stock gauge shows pretty low.

I believe it goes away when I put it into Park, but the gauge stays low.

I haven't changed the oil yet (only had it 3 weeks) but I believe it's currently got 15w-40 in it... and so no, I haven't noticed any sort of increase. What would that be about?

Tys

 

a increase of oil lever could be possible head gasket ie. coolant in the oil or it could be a bad diaphram in the lift pump ie. fuel in the oil

 

What's your idle speed? Could be your idle is set too low. Should be 750-800 rpm warm, in D, with the A/C on. This will help considerably. The *right* idle speed always sounds too fast to me. I tend to think a Diesel engine chugs along happily at about 400 rpm , I set my idle lower once, had the blinking oil light, as well as almost dying engine after a long pull (they do idle slower when warmed up), as well as some pretty serious wet-dog shaking. So I bumped it up to where it should be and everything's been good.

 

Truckerdee, unfortunately, I don't have an RPM gauge built in, or anyone around who has a meter I could barrow... though perhaps I can scrounge around.

yay. another project.

What does that increase (if in fact I am low) do to MPG?

Tys

 

I didnt even know these truck's had a low oil pressure light.and I've owned mine for 11 years now. I would change the sending unit and see if that helps. allways start with the basics. if that doesnt help check it with a real guage.but I would bet you have a bad sending unit.let us know what you find.

 

Bumping up your idle speed won't change your fuel economy at all. Just changes the speed the engine idle's at. I, also, would change the sending unit. They do tend to go bad pretty often it seems.

 

Some newer trucks have a TSB out that requires a "REFLASH" of the PCM to correct for LOW readings from the Oil Pressure Switch.

Don't know if this pretains to 1st Gens or not but here's a link to it.....

http://dodgeram.info/tsb/1999/08-22-99.htm

 

Nope. Our PCM's don't control our oil pressure gauges.

 

This is great. I have the same problem after I get off the interstate and stop at a light. If I was running full throttle for 20+ mins (72mph) on the slab and hold the brake at a stop, my oil pressure gauge drops to zero.

But if I give it just a little bit more gas, then the oil pressure returns and the light goes out.

And yes, it really does sound like it idling extremely low at these times. Too bad, I don't have a tach either.

Let me know when you get this fixed man! I'd love to hear what you had to do.

 

Change the sender, they become less sensitive over time and can give a false low reading.

 

I was a little concerned about my "new" truck. After it warms up the oil pressure would read lower than my other truck, and it rose very slowly from a cold start. I put mechanical gauges on the oil filter housings on both trucks, results were about 70-75 psi cold, and 55-60 psi warm. The stock gauges suck.