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.
Title: Re: 99 Cummins 300 oil pressure guage
Post by: gerdutch on September 24, 2017, 09:44:07 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.

I have a  ISC 350, had a problem with the oil press sender, on the passenger side of the engine, rear of starter.,for which they were famous four. Changed it twice before it cured the problem you describe.