Patrol oil bypass pressure

Hi Aust - I thought at least Roachie or Truckster would come to rescue.
I will ask my mechanic when I see him next, as I am fairly certain he has a workshop manual on our beasts. Will post back here......................Keith

Hi Ray - I visited Mario, my 4wd Mechanic today. He did own a GQ and now has the 4.2 GU - plus he has the official Nissan GQ manual.
We searched it and found the diagram which clearly shows the pressure relief for the oil filter - it is in the body where the filter screws on. Mario said it looks almost identical to other Nissan oil filter housings (eg the 200B etc). Having serviced them, he commented they are not very high pressure - you can depress them easily with a finger. ( I found the same with the the relief valve in the Z9 filter.)

But no-where in the manual - either on the page with the diagram and data, or in the specification pages does it say what the bypass pressure is. It did give the oil pressure as 11psi at idle to 54 psi.

Sorry I cannot give any more detail - it just was not in the GQ manual.
This is a puzzle that definitely needs solving . I wonder if Nissan has a tech email address or phone number....................Keith.

Hi Ray - I contacted a friend who works for a Nissan dealership.
He searched the GU on-line manual. The service procedures are there (simply press and check) and the repair procedure - replace, but again nothing on the actual Psi of pressure release.
He is going to email Nissan HQ and see if he can chase it up.....Keith.

Hi Ray - I rang the Nissan Service guy today, and the Australian H/O did reply to his question, but they simply sent back the oil pressure range : 11 to 58psi.
Either they mis-understood the question, or they also don't know the answer.
He is going to send an email to a Nissan technical engineer in Melbourne.
Will post any reply recd..................Keith

Hi Ray - unfortunately no response from Nissan HQ.
It seems that nobody can answer this very simple question.
No doubt there is an old mechanic somewhere who does know.

Would you mind either posting or emailing me the results of your oil analysis over time? Not the exact details, just the conclusion at 7,500k then 10,000K etc.
I often think that with advances in oil technology (I run a semi synthetic) we should be able to extend oil drains, but the final proof is the actual oil analysis.

Thanks......................Keith

Thanks Ra y - Fax 07 3376 4548
regards.....................Keith