Diesel RV Club, an FMCA Chapter

Technical => Lubrication System => Topic started by: wvabeer on August 19, 2017, 04:23:16 AM

Title: 99 Cummins 300 oil pressure guage
Post by: wvabeer on August 19, 2017, 04:23:16 AM
I just purchased a Newmar 300 Cummins on a Spartan chassis. The problem is the oil pressure gauge, it seems to run a around middle 40's then it jumps instantly to pegged then maybe down a little but never below 42. Any ideas???
Title: Re: 99 Cummins 300 oil pressure guage
Post by: LJ2654 on August 19, 2017, 08:58:30 AM
I know that on a gas engine that a pressure relief valve can cause an issue like this, but not sure on a diesel motor.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: ziggyh on August 20, 2017, 05:33:32 AM
I would put on a mechanical guage and monitor the oil pressure to see if it's a guage or electrical problem or if it is a sticky regulator in the oil pump.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: wvabeer on August 22, 2017, 07:47:07 AM
I would think if the sender was erratic there would be a check engine light or some other alert.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: antiqueclockservice on September 06, 2017, 01:45:20 PM
I think you might better call Cummins tech support at  1-800-DIESELS
Title: Re: 99 Cummins 300 oil pressure guage
Post by: wvabeer on September 11, 2017, 03:16:54 AM
I notice after the gauges do the dance the oil gauge stays at 40 before I start.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: Brett Wolfe on September 11, 2017, 06:12:07 AM
I suspect the dash oil pressure gauge is a Spartan part, and may not even use a Cummins sender.

I would contact Spartan with your VIN and ask them how to diagnose a bad sender vs bad gauge.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: wvabeer on September 12, 2017, 12:02:37 PM
Spartan says it could be a Demux box, gauge or the connections. I'm looking into it.