Hey,

A couple months ago I bought a 98 Ram 1500 5.9, I previously had a 96 with the same engine so I am very familiar with it.

My current issue is the oil pressure gauge dropping to zero when idling after the engine has warmed up. I have searched the issue and it seems that these engines have circulation issues. Once I replaced the sending unit the issue has gotten slightly better but it will still drop to zero at stop lights and beep with the check gauges warning. I just did an oil change with 10W-30 also. What should I do next to try to get this problem to stop? Any help is greatly appreciated and my apologies for starting another thread with this issue but there does not seem to be a common fix after replacing the sending unit.

Thanks,

Patrick

 

Put a mechanical gauge on it, and see what pressure is REALLY doing. May have just gotten a bad sending unit.

 

Is that something I am able to borrow from an auto parts store?

 

I just bought one of their cheapies off the shelf for 20 bucks. Ran it temporarily into the cab, just to see what was going on. Mine was indeed a bad sending unit.

 

If you are getting the same thing after replacing the sender i would think it may be a clogged pick up. What does the inside of the motor(remove the cap on the vc) look like? Lot of dirt/sludge? Get an actual reading from a mechanical gauge to see what the pressure is.

 

I'll take a picture after work tonight and post it. After the most recent oil change I didn't notice anything out of the ordinary.

 

Low oil = bad sending unit, blown out plenum gasket, or the all to well known clogged oil passage. I would try a new manual sending unit first.

 

If you didn't actually have any oil pressure your lifters would be making such a racket you woukdnt drive it.


On a high mileage motor you probably don't wanna know what the actual pressure is... . Haha

 

I was going to do the Hughes plenum fix this summer, but I don't think it is that.

The shop I bought it from had thicker oil in it and it seemed to do it less than when I just did an oil change with 10W-30. I have been driving it consistently for a week and am going to check the oil to see if there was any consumption and I'll get a picture also.

It only drops to zero when I come to a complete stop and even if I just barely touch the throttle it comes back up. If there was a clog wouldn't I be getting bad pressure when driving also?

 

Those are the signs of a failed sending unit. Wouldn't be the first time someone got a bad part, right out of the box.