Low Oil Pressure

[Blzr6.2'83]

My oil presssure is at 10 psi when the engine is warm and at idle with 10W40 oil. It goes up to about 35 psi at high rpm, sometimes almost 40. I just put a new oil pump in so I am pretty sure it is not that. Is this normal or what could be causing this?
Thanks
Kyle

[DmaxMaverick]

Did I read that right, or is that a typo? 10w-40???

To my knowledge, there is no 10w-40 that is compatible with the requirements of the 6.2, or any GM Diesel, for that matter.

The oil you should be using is 15w-40, and nothing else except in extreme cold climates (5w-40, 0w-40). In either case, the API rating should be CG-4, CH-4, or better, CI-4 (which is the latest rating, CG being the oldest).

If you are in fact using a 10w-40 oil, your oil pressure may indicate a reason not to use it. If that is what you have, get it out, ASAP.

[Blzr6.2'83]

I was using 10w-30 but went up to 10w-40 to see if there was a change in pressure. I did not know about the special type I should have been using. What kind of damage could have been done? I have put about 6000 mile on the truck since I got it and probably haven't been using the right oil. What brand do you use?

[DmaxMaverick]

6,000 miles??? That's a long time, even with the right stuff.

I suggest you get some good, cheap oil of the right rating/grade, and change your oil every 500 miles 2 or 3 times. 6,000 miles with an oil that's not formulated to handle soot can leave that abrasive stuff sitting in the nooks and crannies of your engine. You may even consider an engine oil clean-out additive, like Motor-Medic, Bardall, or something like that on the first change. The additive package in Diesel engine oil helps to keep the soot suspended so it can be carried to the filter, or drained, instead of building into very harmful chunks of abrasive grit.

There are many good oils to choose from. Use a brand you trust that is of the correct grade and rating. Your oil change interval on an engine you are unsure of should be around 3,000 mixed miles, and 5,000 miles of highway-only miles (like if you are on a road trip).

I use Amsoil Synthetic 15w-40 "Heavy Duty Diesel and Marine". I have logged over 500K on the original engine with change intervals ranging from 5,000 to 20,000 miles, depending on my driving habits. I did periodic oil analysis until I realized nothing was changing. Filter gets changed at 5K, regardless. I settled on a 10,000 mile interval for the last 250K. Engine still runs strong, but probably won't get 20K more on it for it's well deserved retired life. Good powertrain, but the rest of the truck is really showing the miles. Drove it like I stole it from day one. Never babied, and I over heated it at least dozen times--block heater blew out, water pump froze, freeze plugs, heater core, just about everything that the water touched failed at one point, all after 250K. Heads and block are still original condition. Blah....blah....Ramble....ramble....I must be tired, or something....

Anyway, check the label. It should be rated CH-4 or CI-4 (most of the name brands are now CI), and 15w-40. Good luck!

[Craig M]

Kyle

Chevron Delo 400, and Shell Rotatella T (sp) in 15-40 grade are the two most commonly used oils. Are both readilly available and have good reputations.

[Blzr6.2'83]

Thanks. I hope I didn't mess anything up too badly. I will change the oil today.