Archived Oil pressure alarm!

[btbuchanan]

My 98 12v recently started giving me a zero oil pressure reading and "Check Guages" alarm at idle speed (750 rpm). This would happen only after the engine was fully warmed up. Initially it would occur only after running on the highway and most often when towing. The condition could be corrected by bumping the rpm up a couple hundred. I put a guage on the oil filter housing plug and found the oil pressure was not going to zero. So, I replaced the oil pressure sending unit. Fixed... or so I thought. Worked for 2 weeks and is doing it again. Oil pressures: 65 psig at 1500 and above (hot) and 25psig at idle (hot). These numbers are from the mechanical guage run at the oil filter housing. Seems to be doing it more often now. Running Stratapore filter with Rotella T and Power Up additive. Truck has 130,000 miles on it. Any ideas? Thanks.

 

[R-N-R]

The oil pressure sending unit connects through the ECM.

 

[Joe G.]

You might want to "T" a mechanicl gauge so you can see it in the cab. Compare it to what the stock gauge says in different situations. Then you will know if there really is a problem with oil pressure.

 

[btbuchanan]

The guage on the oil filter housing does not go below 25 psig. I have put a hose on it and run it into the cab, so I know the pressure is not really zero. I think it costs about $50 to reflash the ECM, so perhaps that is the next step? Any concerns about this?

 

[GAmes]

If it's a 12 valve does it have an ECM, or just a PCM?

 

[rweis]

I put an oil pressure gauge in my 2002.



65 psi at 1500 and 25psi at idle are the same readings I get.



My OEM oil pressure gauge only sort of wanders around about the middle reading of 40 psi + - 10 psi when the real oil pressure gauge goes 75 psi cruise to 25 psi idle.



From the real op gauge I think the bypass psi in the Stratapore filters is set at 80 psi. I rarely go over 80 psi. Maybe 1 psi or 2 psi but not much, and only when cold before engine has a chance to warm up to operating temperature.





Bob Weis

 

[The patriot]

My 98 was doing the same thing. It would be about 1/2 gauge, then would drop to nothing all of a sudden. With alarm.

I replaced the sender with a NAPA sender (I believe) and it's been fine, but I havent driven it much.

I had the travel trailer out this past week, and it was fine.

Eric

 

[rweis]

One of the main reasons I added the secondary op gauge is I am not willing to gamble the engine on what turns out to be a DC engineering concocked "gauge". I plan to tow a heavy 5er more and more and you can not make a split second decision weather or not the gauge is "right" and to shut the engine down or not in the middle of an Interstate towing. Therefore the backup.



Bob Weis

 

[Joe G.]

I installed a marine alarm sensor that will turn on a big red light if either oil or fuel pressure drops below 10 PSI. That will attract my attention in case of problems before I would notice it on a guage.

 

[btbuchanan]

Yeah, that's where I stopped first and no luck. Not available to NAPA, Auto Zone, Checker and a couple others. Had to go to Dodge and pay $48 for a $25 part. That would not have been that bad, except the problem is still there.

 

[btbuchanan]

Dodge calls it an ECU (presume "U" stands for Unit).

 

[CumminsPower98]

My '98 12v was doing this so I installed a Carquest sender for $about $52 and it fixed the problem for quite some time then it started acting up again. I then called up the dealer and got one for something like $34. This time the problem went away for only a very short time and now it's worse then ever dropping off many times when at a hot idle. Is this a defective part or do I need a reflash to recalibrate it?

 

[btbuchanan]

I was hoping someone else had solved the problem. For now, I am just living with the problem. I have a guage installed on the oil filter bracket and I know the oil pressure is over 25 psig, even when the in-dash guage says it is zero. I called Dodge and they suggested reflashing the ECU, but I just have not done it yet. If you get to it before I do, let me know if it works out. I think that is what I will do next, unless someone else has had the problem and either solved it another way, or they reflashed and it did not work.

 

[tfarnham]

I also have a 98 12V in a 3500. Which also has the exact same problem.

I reviewed the TSB section of TDR. This problem is addressed with a PCM flash or reload of its software. I am taking a trip to my local dealer to see what that does for it.

Like you, this only occurs with the engine warm, at the stop sign at the interstate off ramp. Needle drops way below zero and the alarms sounds.

Just revving the motor, which always sounds cool brings the needle back up and the alarms turns off.

Todd

 

[tfarnham]

Had the most enjoyable day at my local dodge dealer service department.

called the service adviser on friday, dropped my '98 off sunday evening and on monday I picked up the truck. The truck wash freshly washed, the TSB for the oil pressure alarm fix was complete, all at no charge.

Now only time will tell if this is all it takes.

My '98 is out of warranty. Go figure.

 

[NPierce]

My truck is doing the same thing. I buoght a new sending unit and havnt installed it yet. Kinda sounds like it would be a waste of time to replace it. I think I'll head straight to dodge and see what they say. How did you get it for free? Was there a recall and i didnt get anything? YOUR NOT ALONE!!!LOL

 

[MHowell]

same thing

I have a 99 cummins and the same thing happened to me today! I started it and pulled out of the driveway... pressure went to zero. Turned off, then on again, pressure was fine for about 10 seconds, then to zero. Where can I get a regular pressure gauge that goes on the filter mount so I can make SURE that it is the sending unit. What size is the thread, is it standard?

 

[CumminsPower98]

I just had the PCM reprogramed and it apears to have fixed my problem. My gauge now reads just above 40 psi at idle where as before it was well below 40 and of course would drop to 0 and then back up when first coming to an idle when hot. Here is a link to the TSB: http://dodgeram.info/tsb/1999/08-22-99.htm

Take that into the dealer with you so you can proove there is such a TSB because I had a lot of problems with the dealer I went to as they were unalbe to find this. I called two other dealers and they both told me that it does apply to my truck so I printed it out and took it into the dealer I was dealing with and they got the job done. They said they had never seen this TSB.