I will be replacing the oil pump on my 97 5.9 to attempt to revive my low pressure when at a warm idle that seems to be so common. I'm the original owner and the truck has 176000 miles. I have done DIY oil changes every 2-3000 miles its entire life and about half the time with Amsoil synthetic. The truck has mainly highway miles and is rarely abused. I realize that I may have bearing wear and an oil pump replacement may not cure my issue, but I figure its worth a try. Is a high volume pump the way to go? I can't see my engine being that dirty internally to suck the pan dry. Thoughts? I have read the "Pavemant Sucks" DIY oil pump tech report and it seems like a fairly straight forward job.

 

I don't see it helping, the best thing to do would be to just use heavier weight oil.

 

Her is what the FSM says, The minimum pressure is 6 psi at idle. The normal pressure is 30 to 80 at 3000 rpm or more. If pressure is at zero during idle, do not run the engine.

 

you can replace your bearings with the engine in the truck

 

Actually,

using a HV oil pump is akin to using thicker oil to cover up worn bearings. both mask the problem for a time.

 

A high volume pump does just that. It pulls a higher volume of oil through it into the motor but does NOT significantly increase oiil pressure. To do this you would need a high pressure pump. This done through the use of larger gears and somtimes thinner housings to accomidate them.
I have run both types of pumps in various Mopar engines, and if you are running a high volume pump I would not recommend a stock pan because at high rpms you might start to suck the pan dry. That would be anything above 4000 rpm, but since you have a 5 qt pan from the factory...well, I wouldn't do it. I ran 8.5 qts in a 10 qt sump pan.
A high pressure pump gives you about 40-60 psi cold oil pressure at idle and up to 100 lbs at 2000 rpm and above (cold). High pressure pumps run tighter clearences and heavier relief spings. Many times you can convert a stock pump to a high pressure one. You can run a stock pan because the volume output is the same. Make sure you run a quality oil filter with a hi pressure pump...

 

I bought a HV pump for mine are you saying that was a bad idea? How often are you running at or above 4000 rpm in a truck though

 

... Also wore crankshaft journals, camshaft, etc...

You might be able to change the bearing in the vehicle but if the crankshaft diameter and the camshaft diameter is too small all ready it won't do a lick of good...

If your lossing pressure in might be a good time to do it right and yank it out and get all merasured out properly.

 

One other thing is, if the bearings or crank are worn, the thicker oil and /or HV pump will work like Aim's said (mask or short term help the prob), but, if the prob is a restriction in the block or a clogged screen. Thicker oil or a HV pump will only compound the problem,

 

Mine's gonna be all clean and new so should I be fine?

I believe it was aim that told me what oil pan I need to make it more qts