Thread: low oil pressure high blood pressure!

If that doesn't fix it, don't forget there are 2 pressure relief valves - 1 with the oil pump, and a 2nd in the oil gallery that screws into the block from outside (alongside the governor on the injection pump). It is possible that either relief valve is stuck partially open.

Putting a few things together from your previous posts....
1. Its a turbo block
2. You started to have problems originally after fitting a different filter housing.
3. Problem on startup is like you've just done an oil change and the galleries are empty.

Does your block look like this where the filter mounts:


More info etc here:
http://www.aulro.com/afvb/isuzu-land...ml#post1520401

If so, and you dont have the twin full/bypass filter setup is there any chance that oil is somehow (incorrectly) returning to the sump via the bypass filter return hole in LH upper cavity on the filter housing mount.

It could probably cause both low oil pressure, and draining of the oil cooler and filter housing after shutdown.

Steve

Hello there, both the pressure relief valves are ok, the one in the block seems to be a sealed unit but the valve operates ok and does'nt stick. The block is the same as your photo, l've run it with both the housings shown. The one on the engine at the moment is the original one which used a spacer and remote f/f filter. l took the front prop off and ran it as seen, it did'nt improve things. The other one is the one l'll be using with a remote f/f filter aswell, because it clears everything nicely. l must admit l'm really running out of ideas, but you never know your luck, cam bearings might be the answer. Thanks to you both for your suggestions.