Oliver 1855 Diesel Loosing Oil Pressure

Has 310 Waukasha, reground crank, all new bearings, piston/sleeves, etc.

This has all the updates, and the integral Oil Cooler in the block. It only has abour 43 hours since rebuild. I have only used it during the cooler months so far.

When it is started, it takes about 10 to 20 seconds for oil pressure to read on the gauge, (been doing this since I have got it) but climbs to 50 psi fast.

This is at idle, and stays there till it warms up.

Then when I use it a bit and the engine temp gets in the middle of the operating range, it only gets to 40 psi at full rpm,.. 18 psi at 1000 rpm,.. and 11 psi at idle.

I checked oil level and it is fine. The engine is not overheating. Running 15w40 diesel oil and change it at 20 hours.

Sounds like Oil Pump can't keep up the volume to the engine when hot. Thought of the relief valve, but would be low oil pressure all the time if stuck.

So, it sounds like the Oil Pump.????? Has 4400 hours and believe it is original Oil Pump. I'm always open to suggestions from fellow mechanics.

I am told that is what makes a good mechanic,.. "Someone who isn't afraid to ask for advice !!"

Please put in your 2 cents worth.

I know that up here in Northern Maine we have 10 months of winter, and 2 months of poor sledding,.. So I haven't had a chance to really use it in the heat.

This tractor is my Baby,.. so it is handled with Kid Gloves and not worked too hard and definately not for a long time.

Was double thinking my rebuild,... You know,.. "Did I install the cam bearings right? Did I plastigauge all the bearings after regrinding? etc"

Now, That's a load off my mind. Now I can sleep at nights again,... Wife even knew I was worried about it. I wouldn't of been a happy camper if I have to pull it apart again.

Thanks for that info fellas,.... Really appreciate it,..

Glad to hear you rebuilt the 310. I agree with Wrenchbender in that volume is more important than pressure. Granted, a certain amount of oil pressure is necessary to ensure oil is being circulated up to the turbocharger, but volume is more important. 7 psi is widely considered minimum oil pressure for most engine operation and if you can maintain about 20 psi at 1000 rpm and above at operating temperature, that's as good as any 310s I've ever completely rebuilt. Unless the engine was really mistreated, it is rare for oil pumps to go bad. I believe Oliver deemed anything greater than 25 psi at high engine rpms at operating temperature to be acceptable for the 310. Naturally, it is lower at lower rpms as well. Sounds good here.