OK so I was finally able to find a fitting to getan oil pressuretest gauge on my Disco. Used a 5/16 compression fitting to a ¼" NPT, then a 1/4-1/8" reducer.

Cold:
Idle (~700rpm) 35 PSI
2500rpm = 38 PSI

Normal running temp: (~75°f ambient)
Idle = 20-24 PSI (seemed to vary a bit)
2500rpm = 33-34 PSI

Normal running temp: (~45°f ambient)
Idle =~30 PSI
2500rpm = 35-36 PSI

Castrol 20-50W oil.

Do these readings look about normal to the veterans out there? Or do I have issues?

Manual states pressure should be 40PSI @ 2500rpm at normalrunning temperature. Seems to have best pressure when engine is semi warm, where I'll get the 40PSI reading @ 2500rpm. Seems the hotter the engine & the day, the weaker the oil pressure (thinner oil?).

 

You have a 12 year old truck with some mileage wear so you won't get the factory oil pressure numbers, but the good news is that is great oil pressure for your truck.

 

Thank you Mike! You told me exactly what I needed to know. (and wanted tohear)I kind of figured that in the "real world" and a well "broken in" motora reading less than 40 psi would be acceptable. Just how low was what I was wondering. I can relax a bit now! Thanks again.