Oil pressure problem

I just overhauld my F134. I did most of the work.
The oil pressure is about 40psi cold but seems to drop to less than 10 psi after it is warmed up, Put a new SW gauge on it.
Any help.
Thank You

 

That ain't good (you knew that already). I have had that on engines (not jeep) before. Usually it is a result of slightly excessive main/rod clearances. When the oil warms up it thins out and the pressure drops due to the above mentioned clearances issue. What to do?

1) run really thick oil
2) glue the gauge on 30#, and don't worry about it.
3) tear the engine apart again.

I was told that a engine will survive with 10 psi per 1000 rpm. So a reading of 10 at idle is marginal.

-Hill

 

Not an expert on the 134s, but I have a few comments that might help the discussion. I'd first check the oil pump gear clearance (there should be a spec in the FSM). I'd also check that the oil pressure relief valve isn't stuck open or the spring too weak.

I recall something about the L134 not having cam bearings - that the cam rides in the block. Don't know if this is true for the F134 too, but worn L134s can have a worn-out cam bore and will lose a lot of pressure around the cam bearings. Low oil pressure in an otherwise tight engine indicates a cam bearing problem generally, so that's where I'd look if everything else checks out. Not sure how this would be repaired in a 134 - maybe sleeves? Long ago the recommended fix was another block, or just living with low oil pressure (keep the RPM down).

hth!

 

The f-head does have cam bearings. Is this issue at idle only or any rpm?

 

Cam bearings?

 

Yeah, maybe. Unfortunately you need to take the block to a shop to install cam bearings.

 

I agree with Scott, what is the oil pressure at idle...does it go up with rpm? In my service manual it says Minimum Safe Oil Presure: At Idle 6 psi., At 2000 rpm. (35 mph.)is 20 psi. and Normal Oil Pressure 35 psi. @ 2000 rpm.

Just my 2 cents worth.

 

More detail on the overhaul....

I agree.

kamel

 

I had shop in town that does model A's do the machine work.
Bored the cylinders .060 over, grind the crank, both rod and mains, can bearing, rods resized,valves ground.

New parts, pistons, rod &main bearings,cam shaft, cam bearing, oil pump Meling, timing chain, water pump, tune up parts, seal & gaskets.
This rebuild was done because of a spun bearing on#1 rod,
I do not know if the shop checked the cam bores that do not have bearing in them, could this be a problem.

 

Yes it has gears.
The low pressure is at idle.

 

Isn't the rule of thumb 10PSI for every 1K RPM? Or am I messing that up?

 

This is straight from the Horse's mouth (from the original manual supplied with my jeep)

If it is only an idle thing I wouldn't be concerned about it.