Oil & Fuel NT-204C Low Oil Pressure

[Pirate]

This tractor is about 5 months old. When I start it cold, the oil pressure is center in green, about 60psi. I just changed the oil and filter. When it is hot, after 30 minutes use, the pressure seems to go low, just barely in the green. If I idle it, it doesn't even register an oil pressure. I tried to adjust the oil pressure screw near the filter but that didn't even change it at all. This problem has been happening for a while, both before oil change and after. Any ideas? I don't want to destroy this thing. Thanks.

 

[Affordable]

You can buy a mechanical gauge at any auto parts store,remove your sending unit and screw adapter in that hole and hook up the hose,this will give you a correct pressure reading.Gauge kit is about $ 22.00 your gauge may be out of wack

Tommy
Affordable Tractor Sales

 

[greg_g]

Messin' with that adjustment down by the oil filter can often lead to more problems that it fixes. If you can remember where it was set originally, I'd recommend setting it back.

Many new owners complaining of oil pressure problems are still running the engine on the original oil. It's crap. Drain it, and use a good engine flush (AMSOIL makes a good one). That engine flush, not cooling system flush. Anyway, once all that goop the Chinese exporters call oil is expelled - refill with a good quality diesel engine oil. Everybody has their favorite, but I personally use Shell Rotella T 15W40.

That fixes a whole lotta pressure problems right there. If that doesn't do it, c'mon back and we'll take a second look

//greg//

 

[Pirate]

The gauge has a hose attached to it. It's a Nortrac so it's already had it's chinese blood removed. I just changed it and put in 15/40 rotella. Changing the fluid/filter was my first idea to fix the problem but it didn't change it. No idea where that setting was on the pressure adjustment. I was following instructions in my book to adjust it, BTW changing that setting did nothing to the oil pressure. I spoke with Nortrac later today. They seem to think it is some form of check valve in the filter seat. They are sending me a new filter seat to put on so hopefully that fixes it. Hey greg, I'm USN Retired too and not missing it.

 

[bluechip]

The pressure relief valve on the oil filter will only control the high side of the oil pressure. If your tractor generates 40 to 50 lbs or more cold, than that is either the setting of the relief valve or 100 percent of what the oil pump can generate. You cannot increase low oil pressure by adjusting this valve you can only reduce the highest oil pressure reading. The valve is there to prevent the oil filter from blowing up like a balloon on cold start up. once the oil gets warm it thins and the pressure drops. excess clearance between bearings and journals is the normal cause for low oil pressure, that or a defective oil pump. It is very normal to get very low readings at idle when warm. as little as 7 to 10psi. The engine spec for minimum oil pressure (idle warm) is the line between the green and red on the gage (don't remember what kpg or psi that was it has been a few years since I caluculated and I don't have the books here at home.). If you get 7 to 10 lbs at hot idle, your engine is OK.

 

[RonMar]

The pressure relief valve on the oil filter will only control the high side of the oil pressure. If your tractor generates 40 to 50 lbs or more cold, than that is either the setting of the relief valve or 100 percent of what the oil pump can generate. You cannot increase low oil pressure by adjusting this valve you can only reduce the highest oil pressure reading. The valve is there to prevent the oil filter from blowing up like a balloon on cold start up. once the oil gets warm it thins and the pressure drops. excess clearance between bearings and journals is the normal cause for low oil pressure, that or a defective oil pump. It is very normal to get very low readings at idle when warm. as little as 7 to 10psi. The engine spec for minimum oil pressure (idle warm) is the line between the green and red on the gage (don't remember what kpg or psi that was it has been a few years since I caluculated and I don't have the books here at home.). If you get 7 to 10 lbs at hot idle, your engine is OK.

It might if it was stuck open and bypassing oil when it shouldn't be... Just to be on the safe side, I would reccomend temporarilly connecting another mechanical gauge to verify the pressure.

 

[bluechip]

Good point. I suppose it is possilbe to stick open which would reduce oil pressure across the range. I have just seen too many times people tried to improve low oil pressure by cranking in on this valve. IN fact we just repaird a TY395 engine in an older JInma 354 and after reassembly blew the oil filter up. someone had installed a spacer under the spring in the PR valve in the filter which prevented the valve from opening at all...

 

[Pirate]

I cleaned out the oil line to my mechanical gauge by running the tractor with gauge off. Once the black gunky oil was all out, I put the gauge back on. While running hot the needle stays in the green now. Problem solved.

 

[bluechip]

Great news.