Ok I have some more information that might help...

Engine Cold w/ Standard Dealership Oil...
Idle = 57 psi
3000 RPM = 62 PSI


Engine slightly warmer but not normal temp w/ Standard Dealership Oil...
Idle = 15 psi
3000 RPM = 49 PSI


Engine @ Normal Temp w/ Standard Dealership Oil...
Idle = Maybe 1/2 PSI
1000 RPM = 6 PSI
3000 RPM = 35 PSI

I do not understand why the pressure drops as the engine gets warmer. My guess is that as the oil gets warmer it gets it gets lighter weight and for some reason drops the pressure.

Does anyone care to enlighten me as to why the oil pump would produce less pressure at the same RPMs just because the oil is warmer?

If the oil pump is sending oil through the engine why would things keep getting worse with the bottom end?

I am sure the owners before me took bad care of the truck but if it is maintenanced regularly and properly from now on why would it get worse?

Finally...Since I just got the oil changed at the dealer ship is there any kind of aditive i could add to the oil to make it thicker?

Or do I just need to drain the oil and refill with heavy weight?

If so what would be your recommendation on oil weight?
I live in Florida so it is really hot.

Thanks again,
Zac

The clearance between the crankshaft/big rod ends and bearing gets bigger as the motor warms up, when this happens oil psi is harder to maintain. Try 5w40

And a whole bottle of Lucas. And take out that oil pump and put in a HV oil pump. you may get another 5-10k out of her. But not without a HV pump.

Ok so I would have to drop the oil pan again, to replace the oil pump with a HV one and then I would only get another 5-10K out of it?

What would happen then?

So the issue with my low oil pressure is that my bottom end bearings are worn out?

How difficult would it be for me to replace all the bearings?

Anyone have a tutorial for me?

Download the FSM from here for your year model. It will have pretty good directions for it. However depending on how bad your bearings are, the crank may need to be turned. If i were you i would start looking for a longblock.

EDIT - Posted before end of thread.


Bearings are going to be the issue. Not sufficient. I get 40 psi at idle, and a little over 50 at highway speed. 15 is not enough at idle.

Actually, anything over 10 lbs at idle is considered "acceptable"....

Just changing the bearings may or may not help. Need to check clearances while you have it apart. If clearances are still at the large end of "in spec" when cold, you can bet they are going to be out of spec when the engine warms.

You guys really know how to bring a guy down! I couldn't find 5w40 but I got 10w40 and a qt of Lucas. With the engine at normal temp and the 4 qts 10w40 and 1 qt Lucas the idle is 6 psi and at 3000 rpm it is at 38 psi. Those specs are at the minimum from the FSM so I will try to drive calmly for a little while and get the things done that are needed with my truck and then install the high volume oil pump when i get some free time.

Thanks again,
Zac

P.S. I guess my truck doesn't have a low oil light???? It has never come on so that is kind of scary!

Not to make the job more complicated or an overhaul BUT, I've seen the valley under the intake so clogged and carboned up that the oil drain ports to the oil pan were closed up......oil leaves pan goes through engine VERRRRY Slow return to pan resulting in low to no oil pressure reading. Also teflon tape on the oil sending unit may be interfering with the sensor being properly grounded completing the circuit. Just throwing out a couple of ideas!!

This would require me removing the plemum wouldn't it?

The sensor seems to be working perfectly (based on manual oil pressure gauge) so I don't think that is the issue.