low oild pressure when hot

[41/53dodges]

my oil pressure drops to barely anything on the gauge when the truck is hot (overheated, i fixed that now) is this normal? could the gauge just be innacurate? maybe i should use thicker oil? i have SAE30 now. when the truck first starts, it sits 40 at idle.

[MBF]

Has the engine been refreshed on the lower end (bearings)? Oil leaking around worn bearings will lead to low oil pressure as the oil warms. I've got a Worthington tractor with the same symptons- and I know the bottom end is tired, but that's a project for another day. up. Mike

[1949P17BC]

I would agree with worn main bearings

[razerface]

so what is the oil pressure these engines run when they are correct?

[41/53dodges]

well, i am not about to tear the engine down, as it is running perfectly fine. should i keep using sae 30 or go to 20-50.

does it make any differences that this engine was at overheat when i observed this?

[Merle Coggins]

A higher viscosity number oil might help. What is the oil pressure while driving with a hot engine? As long as it's up around 40 psi while driving you'll be fine. It may be down around 5 or 10 psi at idle, which is difficult to read on the gauge. If that's the case keep driving it until it gets worse or you determine it's time for an overhaul for other reasons.

Merle

[Plymouthy Adams]

once can easily change the bearings without having to do an overhaul..failure to change could result in the need for an overhaul including reconditioned crank..

[carls 49]

A higher viscosity number oil might help. What is the oil pressure while driving with a hot engine? As long as it's up around 40 psi while driving you'll be fine. It may be down around 5 or 10 psi at idle, which is difficult to read on the gauge. If that's the case keep driving it until it gets worse or you determine it's time for an overhaul for other reasons.

Merle

thats the way my 49 runs. no problems and goes down the road great.

[JBNeal]

Similar problems have pointed to the oil pressure relief valve...it probably wouldn't hurt to give it an examination.

[41/53dodges]

A higher viscosity number oil might help. What is the oil pressure while driving with a hot engine? As long as it's up around 40 psi while driving you'll be fine. It may be down around 5 or 10 psi at idle, which is difficult to read on the gauge. If that's the case keep driving it until it gets worse or you determine it's time for an overhaul for other reasons.

Merle

only issue is i only get about 5-10 minutes of driving at a time, only going about 25 tops. im not quite legal yet, so i dont stay out for long or go on main roads

[Merle Coggins]

OK then, check the oil pressure with the engine reved up a bit when hot. Does the oil pressure come up to a respectable level?

[NiftyFifty]

Ok....so I HAD the exact same issue you did...the key word being HAD now...I'm only 30 mins past blowing the engine up in my 50 1 ton....rod went right through the oil pan and all....and to be 100% honest...it ran like a dream right up until it blew, excpet for as soon as it got hot the oil pressure went super low.

I would expect that the oil was getting past the bearings and other spots and I was on a highway trip home "thank god" and got within a mile of my turn when it happened.

If you want to keep that motor in useable shape...investigate more..or be prepared for worst case scenario...

[41/53dodges]

OK then, check the oil pressure with the engine reved up a bit when hot. Does the oil pressure come up to a respectable level?

the pressure pretty much flies up to about 40-60 if i goose it, and thats at about 1600-2250 RPM