Oil Pressure HIGH

[yamajason]

2009 Cummins ISX CM871, rebuilt with new oil pump 150,000 miles ago.
had normal Oil pressure
Idle 20psi
1300rpm 40psi

Then one day after pulling a grade I noticed high oil pressure
1300rpm 60psi and fluttering up/down

After I shut down for a few hours, I started the truck and ran 6 hours home while it had normal pressure
20 idle/40 @1300rpm

Put 1 gallon diesel in the oil 30 miles before oil change shop. Oil changed.

Started truck oil pressure stays at 40psi idle thru 1800rpm

Shut down for a few days, changed Oil Pressure Sensor and restarted engine. Still has 40psi oil pressure at idle.

What do you think is the problem?
(PS I did NOT do the coins in the oil plug mod like some did to raise oil pressure)

[in2trux]

You replaced the sending unit, maybe failed. New doesn't always mean it's good, you know how well this stuff is made any more.
Good reason to have a mechanical gauge as a backup.

Could the fuel be corrupting the sending unit?

[gearhead]

I would definatly put manual gauge on it to see if it really is that high. If it is then mybe spun cam bearings blocking oil flow. I would take off valve cover and take a good look if the manual gauge reads 40. Start it with valve cover off and see if you got good oil flow. If at 700 rpm or so it won't make a mess but if you rev look out big mess lol.

[yamajason]

Where would be best to connect a manual oil pressure gauge to the engine?

[gearhead]

There is small allen plug over on the oil filter housing that you can get reading from. But i would not let this go and keep on driving because it my be a small thing that will only get worse from ferther driving it.

[yamajason]

Pulled cover, took some pics & video from front drivers side to back, to passenger side to front of engine
https://youtu.be/TaVijyxCWfU

[yamajason]

[yamajason]

I did notice the one cam lobe pitted on the 2nd cylinder, it may have been like that from before the half-ass rebuild that was done on the engine. All cam lobes appear to be slinging oil when engine idling.

[Marajin]

(02-23-2016 )yamajason Wrote:  I did notice the one cam lobe pitted on the 2nd cylinder, it may have been like that from before the half-ass rebuild that was done on the engine. All cam lobes appear to be slinging oil when engine idling.

BTW: Most ISX engines have 40 psi oil pressure at startup when the oil is cold. i am assuming you have taken that into account.


Your valve cam is toast! and so is the roller on intake#2 rocker.




This can take out other components as the metal shavings run through your engine!


As fas as spun bearing in the head, the most common place for head to spin a bearing, is on the injector cam side. It is usually between cylinder 3 and 4, underneath where the 2 injector rocker shafts meet. Most of the time, when you get a spun bearing here, the outside of the head on the drivers side will have slightly discolored paint (darker) in the location of the spun bearing due to the excess friction. Sometimes, you can see spun bearings before you even pull the cover off on an old engine if you know what to look for.