Gary_Arnold

Gentlemen, my hunting vehicle has 270,000 miles on it. The engine still runs strong and smooth, and does not use oil to any excessive amount.
What has concerned me since I have had this truck, isthe fact that the oil pressure drops from 38-40 psi when it is first started, down to about 18-20 psi when the truck is running and up to normal temperature. Now obviously, this engine has lots of wear on it. Do I need a higher volume oil pump, or should I change to a more viscous oil than the 10W-30 I have always used to compensate.....I obtained and utilized this truck thoughout the season last year, ferrying dogs and customers cross country thru ranches sometimes two or three full days a week...but I only put about 3000 miles on it last year. I need it to remain as reliable as it has been. Any suggestions to keep her running reliably for a few more seasons?
Thanks,
Gary Arnold

BrianE

I would try 20w-50 oil during summer months and a new oil pump if that don't help. I had a subaru that ran at 5-10 psi for 200,000 miles but that was a 4 cylinder. I did baja the crap out it finally the pump died and so did the car

kcb37

If it is running a minimum of 20 psi at idle that is good. If your running 4,000 rpm that's bad. Generally oil pressure will go up in 10's to every 1,000 rpm. (as a guideline) If it stay's down I would try 15-40 or 20-50. If that doesn't help you may need to rebuild the whole thing. It may just be the pump going out too.

RonH

One of the first places I would check is the oil pickup in the pan. It might be that the pump is starving for oil. A previous vehicle of mine that had a clogged pickup would go low oil pressure after it had run some. It seemed to do it more often when it was hot outside. A clogged pickup could easily be the problem with that many miles.

Gary_Arnold

Thanks for the advices. I will try a little higher viscosity oil first. Then go from there. GDA