Archived Oil Pressure Gauge Goes to ZERO on '98 12 valve

[HerbW]

I've been driving in hot weather for three hours. After I stopped and started to back up, my truck alarms and the oil pressure goes to zero, then back to 40 plus lbs. It did this three times in 50 feet. Searching the archives, I see a TSB that may help. Is this a good idea? Now it is a daily crappy thing. I have good pressure using a mechinical gauge from oil filter.

Thrifty Auto has replacement sender for 65. 00. That's cheap if it will fix it. Has anybody ever grounded or shorted out the connection to see if the gauge stops this on and off pressure crap before buying something now needed? This should tell if the sender is at fault. I want to pull a trailer to the beach next week and want this fixed.

Thanks for advise. Herb

 

[wcjp]

Quite a few here including myself had to replace the factory sender. No big deal. Don't put it off. Some have had the sender start to leak oil in varying amounts as it went bad.

 

[wildmanben]

Mine does that also. I priced a new sender at $36. 99 and a new mechanical Autometer guage was $40. So I figured might as well get the mechanical and know exactly what the oil pressure is. Watching both of them makes me realize how far off the factory one is. The oil pressure bounces around a lot and the factory guage stays at 70psi all the time.

 

[2Gen3Gen]

Just for the record, my 12v 98 had countless senders replaced, all under warranty. The local dealer even replaced them after the warranty since it was a known ongoing problem. I know of a few other guys with the same problem. Good luck

 

[Flinty]

oil pressure sender

Mine did the same thing for the first time today, scared the crap outa me. I just fired up the computer to do a search. I have read threads where the sender fails and then proceeds to spew mass amounts of oil all over the engine compartment. Sounds like a real treat.

 

[nersasian]

Just had mine fixed a few months back. The dealer told me I needed a new motor, HA!

I took it to a certified cummins dealer and it was just a bad sender. Changed it and all is fine.

 

[HerbW]

FYI about the change from Herb to help you do the same!

Well yesterday I got the right oil sensor/sender for my truck. It costed 38 dollars from NAPA. The Dodge dealer ******* wanted 65 dollars. The new one is guaranteed for one year. To remove the plug from the old, there is a red tab that has to be slid sideways. Then, you squeeze the plug near where the wires go into it to release tab and pull at the same time. You have to do this by feel due to the location. I was then able to remove the old sender with a 1 1/16" very deep socket. They sell a socket at NAPA just for these senders! If you look thru the left wheel skirt next to the shock tower you can see and get to the sender with socket extensions after pushing on the socket over the sender from reaching up above. I hung a light from above to see what I was doing. There's not enough room for socket along tower. reinstalling is just reverse of removing. The Service manual says 144 ft lbs. Other TDR members and myself think that is nuts due to it being only a 1/8" NPT nipple. I tightned it it it felt snug and no more. I am a real believer it torque specs though. If Piers or other diesel techs know the torque, please advise me and I'll redo it and correct my Factory service book for the next time. I hope this info helps others fix their sender.

It fixed the problem and once I figured out what to do, it was quick! I'd be glad to help anybody in the Portland area.

FYI,I took the old sender apart and it is a variable resistor type made with wraps of wire and a sweep arm like a fuel sender. This makes me believe that the pressure on the gauge is a good representation of real pressure.

Thanks, Herb

 

[RustyJC]

The Service manual says 144 ft lbs.

A misprint perhaps - 144 in-lb (12 ft-lb) would probably make more sense.



Rusty

 

[tfarnham]

Our '98. 4 12 Valve had the same symptoms last summer.

I checked the TSB's. Took it to Sundance Dodge in Boise.

Dealer took care of the PCM program thing. Have never had any oil pressure problems since then... . knock on wood... ... .

 

[norcalram]

Same thing happened to mine. There are numerous threads on this, I even posted one with pics as no one knew about the "red tab". I pulled and pulled until i found that!

I replaced mine, it worked for a couple of months, then started dropping to zero again. did this for awhile then suddenly quit and has been working fine since. If you have the dealer perform the reflash, it just trains the computer to read the sender as an idiot light, pressure/no pressure.