Oil pressure gauge reading incorrectly?

[captncrunch]

I have a ISC 330 in a1999 Alpine Coach ,when cold and at high idle the oil pressure is below 25lbs,when it warms up and take it off high idle the pressure goes up to over 55lbs when I rev it up the pressure drops again,just the opposite of what it should be (faulty gauge ??) any suggestions ?? captncrunch

[Luckiest Dreamer]

Could also be the senser.

[EngineerMike]

Probably the gauge sensor. I believe the ISC has two senders, one for gauge & one for ECU.The following from my notes taken off other iRV2 posts:
Oil Pressure Sending Unit: for 1998- VDO 360009 located forward of the turbo, aft of the location for coolant “filter” and on top of the oil filter housing. To diagnose VDO sender, ohms w/engine off should be ~10, with ohms increasing as oil pressure increases up to vicinity of 240. For non-VDO senders, engine-Off ohms ~240, with ohms decreasing as pressure builds.
If that's how its always been since you've owned it, could be somebody replaced a VDO sender w/a non-VDO?

[captncrunch]

Thanks Mike
Possible to identify which sender it is other than with a multimeter?? would a part number and check with Cummins parts identify which sender is for that engine?? Captncrunch 1999 Alpine Coach/330 ISC Cummins

[Old Scout]

Find and then take your engine's serial number [usually on the timing belt cover[rear of coach/front of engine on passenger side]] with you to Cummins. They should have all the diagrams on/for your engine. Hate to "diagnose" problems by buying new parts but sometimes it just easier--not cheaper--but easier.....good luck.....

[Wil Rathke]

Had an oil pressure sender problem with our '99. The oil pressure sender for the dash gauge was a VDO and was installed by WRV and not a Cummins part. EM probably has the correct VDO PN but if in doubt remove it and look at the PN on the sender. I ordered one online.

[captncrunch]

Hello Wi
I found the same issue at Cummins,this sender was installed by WRV
also there is no pn# on the sending unit just VDO Germany no numbers
it has 2 wires on it also found 1 wire without a nut on it Thanks CaptnCrunch