2nd Gen Non-Engine/Transmission Oil pressure gauge problem

[hamachi]

Having problems with the oil pressure gauge on my '99. When I turn the key on to the acc. position, the gauge shoots up and reads normal pressure. After approx. 30-60 seconds, the gauge pegs to zero and the check gauges light illuminates.



Upon starting the engine, the gauge will do the same thing. After several minutes of driving, it will shoot back up to normal for a time, then peg at zero.



I disconnected what I believe to be the sending unit, (under forward part of the fuel injection pump), and the same thing happens.



Is there some sort of gizmo in between the sending unit and gauge that could be shot?



If it's the sending unit, where can you get one other than the dealer, which wants $210?



Is the thing I unplugged actually the sending unit?



Is the thing that plugs into the right side of the engine with a rubber plug attached with a silver knurled knob the water temp sensor?



Thanks.

 

[BFC]

Definatly the sending unit. The oil pressure sensor is actually right under the ECM a little closer to the fire wall. You should see a three wire plug going to it.



You can get the sensor from any Cummins dealer, part#3408428, paid 69$ for mine. Takes less than 5 min to swap,all you need is a 32MM deep socket.



Hope it helps,



Glenn

 

[Alan Reagan]

Also, look at the TSBs. I don't remember the years covered but there is a TSB on this problem that is an ECM software related issue instead of the sensor.

 

[BFC]

Originally posted by Alan Reagan

Also, look at the TSBs. I don't remember the years covered but there is a TSB on this problem that is an ECM software related issue instead of the sensor.

Don't let them reflash you truck for this!! All you get is useless gauge in the dash that always on 60. It was cheaper for DC to do a reflash then to replace the sensor.



Glenn

 

[Alan Reagan]

If the sending unit is OK and it's an ECM problem, what do you do then. I agree, his problem is probably the sending unit BUT..... what if it's not. This is not a good situation.

 

[Shovelhead]

What brand of oil filter are you using?



Bookmark this site.

http://www.dodgeram.org/tech/dsl/mt_2_feb98/fuel_sys_comp.htm



Excellent resource info on the Cummins.

 

[BFC]

Originally posted by Alan Reagan

If the sending unit is OK and it's an ECM problem, what do you do then. I agree, his problem is probably the sending unit BUT..... what if it's not. This is not a good situation.

Yep it sucks, I'll give ya that. When it happened to me, I changed the sensor, if problem had persisted, then get the reflash. Guess what? I didn't need a reflash.



Glenn

 

[hamachi]

I found the sending unit - thanks BFC. Now I have to find a 32mm deep socket. Then it's off to Cummins Northwest for a sending unit.

 

[hamachi]

Picked up a new sending unit at Cummins Northwest, (part no. 4088390), for $69. Then on to Tool Time for a $17. 95 32mm deep socket.



Just installed it and the problem is fixed!



Thanks again to Glenn.

 

[BFC]

No sweat dude, that's what this site is all about. The way I look at it you just made up you 35$ subscription and then some ! Any more questions LOL.



Glenn

 

[KSTRS]

Before you spend your cash, I'd talk to your dealer again. The sending unit went out on my '98 12v at about 82k & dealer replaced under 100k powertrain warranty. Just a thought, sorry if I read this late.

 

[hamachi]

I contacted the dealer who of course said it wasn't covered. I think I'll call Cummins NW and see what they say.