Another oil pressure thread

[Rawze]

(11-15-2018 )Peashooter67 Wrote:  ...
Because of Rawze, his suggestion with explanation, I’m plastigauging main and rod bearings.
His theory and explanations made since and fit the symptoms.
...

Just repeating what I have seen in the past, or others have shared with me. I have never claimed to be any kind of professional, just someone who tries to help others with the little bit of twisted knowledge I have stuffed into my head.

(11-09-2018 )Peashooter67 Wrote:  ...

Cold at start up oil pressure is 45-50 psi at 600 rpm.
This is measured at sensor on driver side and on main oil gally on passenger side with mechanical gauge.
Once water reaches 180 and oil 220 degrees oil pressure drops to
8 psi at 600 rpm and max is 22psi at 1400 rpm.

No matter where you test the oil pressure it’s 8 psi at 600 rpm.

This would indicate you have shimmed the pump with the equivalent of 6 dimes?. When cold, it is regulating the pressure to 45~ish psi?. Does it stay at same pressure when cold and you rev it up?. -- If so, then that is an indication that the oil is flowing into the engine, down the back side of the gear cover, then back to the regulator inside the pump properly anyways. Would indicate there was no restriction (bad o-ring floating around) in the regulating feedback circuit.

Maybe someone flipped the end piece for the regulator if they had it out while shimming the pump?.




You also mention there is a lot of oil up top in one of your posts?. Maybe compare it to your other isx?. If there is a lot more oil flow in the top of the head than your other one, that is an indication something in (or something installed into) the new head may be incorrect / still hemorrhaging oil?.

Has anyone blocked off the turbo feed line to see if the pressure comes back?

Maybe drop an inspection cam into one of the drain ports on the side of the block to see the oil flow out of the engine, turbo, and other areas going into the pan?

lastly, has anyone considered sending oil off to see if it is diluted / getting thinned out with fuel? - just more blind guessing here.


Possibly something wrong with the front gear cover/housing itself and its cross-channels?.

Just more guessing here. I know if it were mine, I would have been driven crazy until I found it too.

There used to be animations / videos on youtube of the oil flow and feed system for the ISX that a person could watch with full detail through the block, head, engine brakes, etc. but it has since been taken down. Maybe someone can PM you a link to it if they still have a copy of it saved somewhere, since it is not public any more.