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Topic: High Oil pressure - Cummins 8.3 ISC (Read 366 times) previous topic - next topic

High Oil pressure - Cummins 8.3 ISC

I have a 2000 U270 with 140,000 miles on it.  Owned for 3 1/2 years.  oil pressure has always been in the 40-60 psi range at highway speeds and around 20 at idle when hot.  Drove to Angel Fire, NM last week from East Texas (700+ miles)  everything normal.  boondocked a couple of nights and started up in morning ( 45 degrees outside) and cold start pressure was 77 psi.  I had never seen that before and was concerned.  Eased into town and set up in rv resort.  Got a manual gauge pressure check and it was 80 psi at cold start.  Mobile mechanic agreed that seemed high.  I replaced the oil pressure relief valve.  No change.  I changed oil and filter (Oil and filter was changed prior to trip)  Rotella 15-40, nothing different.  Limped into Amarillo to Cummins Service after talking to them.  Drove 55 mph and generally kept pressure between 50 and 70.  2 days at Cummins shop and evaluating.  Replaced oil plunger and spring in oil cooler, no change.  Did a series of tests with mechanics and engineers and they could not explain the change I saw.  Ultimately, they said it is within spec, just let it warm up good before driving.  Needless to say that is a little disconcerting when I had a steady pressure reading both at the dash and on my blue fire in the 40-60 range.  It can now get into 80s and 90s if rev'ed before hot.  Cummins did this in their testing.  Telling me good to drive home from Amarillo to Tyler in the morning.  Any thoughts about this?  Anyone aware of similar issue with sudden higher pressure?  These high pressures were seen on old gauges(dash and ECM) and manual gauge.

Re: High Oil pressure - Cummins 8.3 ISC

Reply #1 –
Still thinking on this one,what oil filter did you use? Did they take the readings at different points on the engine?
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: High Oil pressure - Cummins 8.3 ISC

Reply #2 –
Quote from: John44 –
Still thinking on this one,what oil filter did you use? Did they take the readings at different points on the engine?

When you said you changed the oil and filter, did you also change after you started seeing this problem,  even though you had just changed it?
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: High Oil pressure - Cummins 8.3 ISC

Reply #3 –
Yes, I changed the oil and filter both before the trip and after the issue rose.  First time was a Fleetguard filter and on the road, it was NAPA filter as it was what was available.  The pressure was checked manually in multiple locations at Cummins.  They acknowledged the pressures were higher than before but said they thought it was within spec for Cummins.

Re: High Oil pressure - Cummins 8.3 ISC

Reply #4 –
If it were me I would look on Ebay for a parts book and a service manual,then look and research any other component that would affect oil pressure and go from there,I would run it like Cummins said and watch your pressures and temps,you may never find
an answer.
96 U270 BUILD 4810
85 380SL
Drummonds TN.