Need advise on oil pressure!

[thetester]

Hey guys I have a 20 hp farmpro / jinma actually a 2420. I’ve been battling for a while!

I’ve resorted in a complete rebuild inside and out. Everything is brand new! Yes oil pump also.

When I first cranked it up I would get about 20ish lbs of oil pressure at a little above idle. When I reved the engine towards the upper end, I could reach about 40ish.

I’ve put about an hour on the thing to break it in and now all I can get topped out is 20 lbs. At idle it’s about 5-10!

I have no idea what this thing calls for as what the pressure should be at all.

To me this seems low but I don’t know.

I’ve attempted to dicker with the pressure regulator on the oil filter housing and I get no change no matter what I do.

Any advice ideas or is this just normal??

 

[Unclewillie]

Hey guys I have a 20 hp farmpro / jinma actually a 2420. I’ve been battling for a while!

I’ve resorted in a complete rebuild inside and out. Everything is brand new! Yes oil pump also.

When I first cranked it up I would get about 20ish lbs of oil pressure at a little above idle. When I reved the engine towards the upper end, I could reach about 40ish.

I’ve put about an hour on the thing to break it in and now all I can get topped out is 20 lbs. At idle it’s about 5-10!

I have no idea what this thing calls for as what the pressure should be at all.

To me this seems low but I don’t know.

I’ve attempted to dicker with the pressure regulator on the oil filter housing and I get no change no matter what I do.

Any advice ideas or is this just normal??

The oil pressure gage may be faulty or giving faulty reading , sometimes gunk gets on the end in the engine during rebuilding.

 

[Unclewillie]

I would think at cold start (80 degrees) it should read around 45 and drop to around 30 idle warmed up.

 

[Bob Rooks]

5 to 10 psi at idle on a warm engine is acceptable. 20 psi at high idle is about 10 psi less than I'd like to see.
What oil are you using?
Did you install a new/reground crankshaft with appropriate sized main and rod bearings?
Did you have cam reground, and with new bearings correctly oriented?

 

[thetester]

Well It’s a brand new mechanical gauge. I would hope it’s not that. Before I rebuild it and the main reason was low oil pressure.

It’s strange... I was also thinking it should hover at 40-45 then drop to about 30-35.

At real low idle it’s as low ad 5-10.

 

[thetester]

Any ideas on what to check and how to go about it??

 

[Bob Rooks]

Any ideas on what to check and how to go about it??

Did you Plasti-Gage any of your bearings?

 

[thetester]

It was a brand new standard crank. New cam new bearings. All brand new and no need to gage. Everything but the head and block is new.

 

[Cougsfan]

All brand new and no need to gage.

Not sure I'd buy into that philosophy. Did you replace/rebuild the oil pump? Does the oil pump have a pressure release that may be faulty?

 

[thetester]

Not sure I'd buy into that philosophy. Did you replace/rebuild the oil pump? Does the oil pump have a pressure release that may be faulty?

Yes brand new pump.

The pump is gear operated internal design. I’ve seen no sign of a relief made into it. The only thing I know that’s on this tractor is what I think to be a oil regulator in the form of a spring and ball bearing tensioned by a set screw.

It is located on the oil filter housing.

I am using mobile delvac 15w-40