Another oil pressure thread

[Rawze]

Only thing that can cause oil pressure to be that low (8 psi) that I can think of it that it is likely internally homoraging oil badly somewhere. That or the oil filter is plugged up?

Common mistakes during an inframe just some random guesses here. Some of this it sounds like you have ruled out already ...

* oil pump shimms installed incorrectly (upside down), allowing oil to leak past them. Seen that one a few times.

* bad oil pump? - I have seen new ones with problems sometimes. Taking it apart will reveal what is wrong if it is bad internally.

* Oil filter bypass valve update installed incorrectly or o-ring shear.

* Bad oil cooler?, leaking internally?. not sure if thats possible, Have not had to take mine out yet.

* A spun bearing somewhere.

* incorrectly fitting, or damaged piston cooling nozzles.

* Improper install of one of the rocker/injector shafts or their retaining bolts.

* Bad o-ring in pickup tube, oil pump sucking air?.

* Damaged oil pump.

* Damaged internal passage in engine block?

* Air compressor bypassing too much oil ?

* The lower concept idler gear (first gear above the crank) is also positive pressure feed. A bad bearing / misalignment of sort could cause problem / low oil pressure too. The adjustable idler gear is also positive pressure fed.


* has anyone eliminated the turbo oil feed line temporarily to make sure it is not bleeding too much oil through it?


What brand of rod/main bearings were used? OEM or aftermarket?. if any aftermarket bearings are used ... THEY MUST BE PLASTIGAUGED AND CHECKED BEFORE ASSUMING THEY ARE GOOD!... that is one of the reasons why I will never will use aftermarket bearings or overhaul kits inside an ISX engine. Has Anyone plasitgauged the bearings for excess clearances?.

AND THEN there is the well known issue of ISX engines having alternate size rod/main bearings in them randomly sometimes. Mechanics these days are notoriously under-trained when it comes to this, and it is a real issue that will cause lower then normal oil pressures. here is more info on this...
http://rawze.com/forums/showthread.php?t...5#pid32065