I have an 05 Dodge 2500 4x4 with 2000 miles. I noticed while pulling the other day that when I let off the pedal that the oil pressure dropped down to the "lowest part of the white bracket" or 20 as far as I can tell on a stock gauge.

Is this normal? What is ok?

 

Put a service gauge on it to verify , its sounds like a ground prob. creating a voltage surge , so next do a voltage drop test on the + and a res. test on the -.

 

The gauge in the dash is not real. It is an idiot gauge. You'll need to hook up a real oil pressure gauge if you want to know what it is operating at.

I recall that the DRB scan tool doesn't even provide an oil pressure value for my friends 04.5 600. In fact the new version of software has about half the information as the version for the 98.5-02 trucks has.

 

true. as there is no pressure sensor in the lube oil system. only a 6psi switch.

 

Yep, Nick is right. That 6psi switch simply activates the check gauges light once oil pressure gets that low. Pretty silly on Cummins part since they specify that the minimum operating oil pressure at idle is 25psi. By the time you are at 6psi it's almost too late.

 

below if from the factory service manual:

 

the guage fluxuations are a programed feature of the instrument cluster dependant on temperture and rpm, like was said, realy stupid