Engine/Transmission (1998.5 - 2002) oil pressure guage

[blkdragon]

I have a 99 and the oil pressure guage never moves it stays the same whether it is at idle or a 3800. I was wondering if this could be a bad sending unit or something. The oil pressure guage also reads very high almost 80 all the time

 

[jkalchik]

I've also got a 99 24v. From my research, the dash gauge flat out LIES. Apparently, there's an issue with the sender, and rather than fix the isse, there's a firmware upgrade that pegs the gauge at a specific reading UNTIL THERE'S AN OUT-OF-SPEC indication from the sender. Which, IMHO, is too late.



I plumbed in a Westach oil pressure gauge into the test port on top of the fuel filter housing. *VERY* enlightening.

 

[Joe Mc]

My 99 has always been dead on? I checked with a mechanical gauge and it was a few pounds higher but that was consistant through the ranges. When it's cold out or fresh oil change it'll go up to like 80 until it reaches operating temps then down to 40 at cruise, a bit less when I'm at a stop and around 35 when idling in park/neutral. I'd change the sending unit. Don't get the firmware upgrade - change out the sender.

 

[MSnow]

I'v got a 98. 5 with 130000 miles on it. The oil pressure gauge s**t the bed about a month ago. It works for a couple miniutes when first started then goes to zero. I think i'll use jkalchik idea. Better than $250 for a new sending unit.

 

[jkalchik]

Joe, never get a firmware update from the dealer then. I think you'll get saddled with the "fix".

 

[TKeeler]

What is the right part number

I'v got a 98. 5 with 130000 miles on it. The oil pressure gauge s**t the bed about a month ago. It works for a couple miniutes when first started then goes to zero. I think i'll use jkalchik idea. Better than $250 for a new sending unit.

My 98. 5 has started doing the same thing... I about had a heart attack the first time it acted up #@$%! I would like to fix it with the right part... a sender and not a switch but there seems to be some confusion at least on my part as exactly which part number it is. Is it 4921511, 4076930 or 4088390? I have found the 4921511 at www.scheiddiesel.com for $90. 00, I would hope that is a sender and not just an idiot light switch for that price.

 

[BHaus]

The correct Cummins p/n is 4088390NX I paid about around $70 last year. This one works exactly like the original, gauge works like a real gauge, not an idiot light. I was told they are getting scarce, so you may have to check several Cummins shops. Good Luck!