When i start my truck it takes a long time to build oil pressure. Changed the oil and the same thing happened. I had the truck idleing today while checking the AC and walked back to my truck and the guage was reading 0. I only seem to have problems when i start it up or it's idleing. When i start it and can't get pressure I rev it a little and it slowly comes up. After i take off and drive a little i have no problems unless i shut it down. Any help people.

 

If you have OE gauge then I would suspect a bad sender unit. Does the engine make any unusual mechanical noises when this happens? The only way to really know for sure what is happening is to temporarily (or permanently) install a mechanical gauge and then go from there.

 

On top of the oil filter housing there is a 1/8" NPT plug...remove it and screw in a 1/8" NPT bottom mount pressure guage (0-100 psi). This will verify if you in fact have oil pressure.

When the senders go bad it will usually register pressure, then go to zero then register pressure again...kind of an up and down thing. But as Stan already pointed out - I think its the sensor too (provided you DID remember to put oil into the engine)...

 

I believe a '99 doesn't have oil pressure signal directly from sending unit. It's the PCM that runs the gauge, doesn't it ?.

I know there has been many issues about this, when oil pressure was dropped immediately while driving and people though of serious damage, in fact I believe there's a TSB on this.

After you check with pressure gauge to be sure oil press is there, you might want to take it to dealer to have it checked. Also somebody with a good scanner can check oil press at idle.

 

I would be careful getting the dealer to "fix" the oil pressure gauge , the TSB just gets them to re program the PCM/ECM (whichever it is) so it puts the gauge in the safe range and leaves it there. In other words , it makes it COMPLETELY useless.

 

JKM is right on this. Dont get the flash done!

 

ok i put a mechanical guage on and it still says i have no pressure at an idle. If i am driving it is fine but if i stop at a red light too long or i just start it up i have no oil pressure until i start driving again. I have not noticed any unusual noises and i even got under the hood when it had no pressure. I also changed the oil filter tonight and still acts the same. Some one help me i'm a little worried

 

This may sound sillly....

1) Check to make sure you have not stacked oilf filter o-rings...ie, sometimes, the o-rings gets left hanging on the oil filter/cooler assy & the new oil filter gets installed on top of it. This usually shows up as a BIG leak.

2) What is your oil level? In safe or hi safe range?

If all else fails, maybe take it into a cummins shop....

HTH

Tony

 

You're not running a Fram oil filter, are you?

 

no i run wix, nad truck only has 135k miles

 

Wix.... is that the NAPA brand?

 

Wix private labels some of the napa oil filters....Napa label = Wix filter.

Tony

 

I have the same problem right now - still need to verify oil pressure with a guage

 

I had this problem on my 2001 2500 RAM and it turned out to be the oil pressure sensor ,which was $235 to buy from dealer. Ididnt have a pressure gauge to hook up ,but a buddy of mine removed the oil filler cap and wiped the oil off of the lifter and immediately it was covered with oil ,so we knew the oil pump was still pumping.

 

it ended up being the oil pressure regulator plunger beside the oil filter housing was stuck wide open. Replaced and the truck runs fine.