I have read a lot about this issue, so I did replace the sending unit, same issue, did a pressure test warm under a load 5 - 7 PSi, is that enough to keep it going or is it time for a oil pump? I just bought this truck for my son and I do not want to put a new engine in it. any suggestion would be great.


Mike

 

Are you saying that it checked 5 to 7 psig oil pressure with the engine revved up? If so, that is way too low. Should be 15 or so at idle and 40 and up revved up.

 

Agreed ^^ with Roadie

7 psi is pretty low, Old style engines might have survived with that kind of of PSI. Really doubt that these modular can. Odds are good that the bearings are shot.

 

No 5-7 at idle with a load, rev engine at its over 50psi

 

How would I tell if the bearing are bad? and would a oil pump replacement be my first repair for this issue

 

A new oil pump might help and it may not. How many miles on this engine? Worn bearings cause more oil to escape between the crank or cam and the bearings and reduces oil pressure. When an engine is revved, the pressure is controlled by the relief spring in the oil pump. I think if it were mine, I would use a slightly higher viscosity oil such as 10w30 and see if that changes the idle oil pressure. I'm assuming the engine isn't knocking.

 

Could also use one container of STP additive.
It's good for about 10 psi. increase average on a trial test.
My 262,000 mile 4.6 still hot idles at 24 and runs 50 psi at road speeds of 65 mph in OD.
Good luck.