What oil pressure is too low

Anonymous-0 · Sep 27, 2011

The oil pressure gauge on my 706 starts out with 40 lbs. but after the engine warms up to working temp the pressure is down around 20 lbs. Is this too low and if it is what needs to be done? I have straight 30 weight low ash oil in it now and it uses about a quart every 4-5 hours of hard work. Doesn't smoke at all and starts and sounds good. Thanks.

Allan in NE · Sep 27, 2011

General rule of thumb is that if it is above 8 lbs, it should be okay.

If it gets lower than that, you'd better take the time to fix those bearings before it gets into the crank.

Allan

d282 · Sep 27, 2011

I am curious as to what the experts will say as I have always wondered myself. Mercedes says you need 7psi of oil pressure for every 1000 RPM.

Dave_Id · Sep 27, 2011

The engine in my IH 275 swather ran at about 15 Pounds at fast idle, at slow idle, zero. I only used it one day out of the year, and it never smoked, so I never rebuilt it. Ran like that for me for 5 years, I sold it, and the guy who bought it from me is probably still using it the same way.

pete 23 · Sep 27, 2011

The exact oil pressure is not the problem. It is a change from the normal pressure that is. A chevy six with dippers on rods had 14 psi max. An H farmall will run about 70 psi max. So, if the H only puts out 14 psi you have a problem, chevy six was fine. If you have the aluminum oil filter base I suspect the pressure relief valve is shot. Easy fix. They originally had a fiber wafer and it erodes and leaks pressure. Might be oil pump end plate if valve is good. After that, think bearings, but if it holds forty psi at higher speeds it will not cause a problem.

Janicholson · Sep 27, 2011

The plain bearings in normal internal combustion engine do not rely on oil pressure to float the insert over the journal. They rely on a continuopus supply of oil to refresh that squeezed out. If the pressure is sufficient to get oil to the bearings, it will be fine. Exceptions are bearings and pistons cooled by the oil. The reduced flow of near no pressure can overheat journals that are subject to high temp. Jet orifices directed to piston skirts that do not supply sufficient volume far enough will cause burned pistons and siezed engines.
Engines with hydraulic Lifters or other hydraulic Oil pressure related adjustment systems (including cam timing) will not be happy. Old simple tractors live with little pressure for a long long time. (not recommended) Jim

David G · Sep 27, 2011

You could try moving to 15W40 and see if that improves. I switched to that on mower and a lot less blow by.

Tom Fleming · Sep 27, 2011

Well, if you look at an original IH oil guage, there is quite a spread of white indicator color. the red portion is small. Would be interesting to see what the pressure is for the line between red and white...........

F-Dean · Sep 28, 2011

That is close to what I had heard, "10 PSI per 1,000 rpm." In other words, what is okay for a F-20 may not be okay for today's higher rpm tractors.

What oil pressure is too low

Anonymous-0

Well-known Member

Allan in NE

Well-known Member

d282

Member

Dave_Id

Well-known Member

pete 23

Well-known Member

Janicholson

Well-known Member

David G

Well-known Member

Tom Fleming

Well-known Member

F-Dean

Well-known Member

Similar threads