Powerstroke oil pressure gauge=vacuum gauge?

[Shaman]

Maybe I am not used to a guage that moves, but when riding in a bus with a PS engine, I noticed that the oil pressure gauge would drop really low when the driver would get on the gas. Is this normal for PS engines?

 

[mechtech2]

No . It is backwards. Did you see another gauge that you thought was the oil pressure?

 

[Hammer]

Actually, this has been observed, especially PSD's modified with Twin high pressure Oil pumps. At high throttle, the High pressure oil pump increases demand on oil in the High pressure oil Reservoir. This increased demand shows as a lowering of engine oil pressure as the Low pressure Oil pump is now supplying more oil to the HPOP reservoir and thus less oil is flowing to the bearings.

 

[Chris142]

I had a Scout that had really worn Main bearings. Getting on the gas would make the oil pressure drop about 15psi. I'm assuming that this was because the crank was moving away from the oil holes in the top of the main bearings and opening up the clearance which dropped the oil pressure.

A new set of mains and rods fixed it.

 

[Shaman]

It was the oil can symbol mechtech. The bus was probably not in the best shape, and without a doubt not modified. Just to clarify, I know that diesels don't necessarily have vacuum, but the needle dropped as the throttle was increased.

 

[tom slick]

Dropping oil pressure as the RPM go up can indicate (very) worn rod bearings.

 

[mechtech2]

Powerstrokes are unusual diesels.
But they are common in work trucks. I have never seen ANY engine get lower pressure when revving the engine up.
Maybe the gauge system is faulty?