Ford 1900 low oil pressure possibly

stevem5215 · Sep 11, 2015

Hello all Tractor experts, I have a Ford 1900 3 cyl that started last fall flashing very intermittently the low oil pressure light. This spring, along with my normal yearly oil change I put a new pressure sensor on it. It didn't flash for a few months and then a couple months ago it started again. Just briefly at first and you would miss it unless you were staring at the console. I then figured I'd try a heavier oil in it so I went to 15w-40 like I use in the chinese Jinma. Again it seemed to slow the flashing. When it got very hot here in the 90's in the last two months it started again. In the last couple of weeks it's gotten worse and it isn't on solid but it's flashing and getting near solid.

So, I'm thinking i've got either a real low oil pressure problem with worn main bearing journals (tractor has 1200hrs on it). Or I've got a false low pressure light due to sludge or something. Or it could be a real problem with the oil pump. So, if it's the oil pump, has anyone changed one and where is it at on these things. Drop the pan and swap it out easily ? Looking for suggestions..

Thanks,
Steve

bg71361 · Sep 11, 2015

You need to get a real reading try plumbing in a mechanical pressure gauge, and see what results you get.
Good luck.

moriboy · Sep 11, 2015

I just experienced something similar with a new to me dozer. First time I really ran it I noticed the oil pressure on the factory gauge would barely read 30psi at almost full throttle. When idling it dropped to about 7. I was worried I brought home a lemon. I ran down to Napa and grabbed a good quality mechanical gauge and hooked it up. I hit the key and at cold idle I was reading 42. I ran the heck out of the machine for about 3 hours and my hot idle pressure is 34 and at close to full rpm its at 55. Boy was I relieved! At 1200 hrs, I would think it's almost impossible that you have worn main bearings.....

Fawken · Sep 11, 2015

As stated above it isn't hard to hook up a gauge temporarily and check. The one thing that bothers me in your post is the 1200 hours. If it is like most of the Shibauras I've ever seen from the early 80's the hour meter flips to 000.0 at 1000. Could just need a good flush to get sludge out of the pan.

Jerry/MT · Sep 14, 2015

bg71361 said:
You need to get a real reading try plumbing in a mechanical pressure gauge, and see what results you get.
Good luck.

Hookup a reliable gauge to measure the oil pressure directly to verify the problem. If it measure less than the OEM specs, get a factory manual and read up on how the lube system functions. At 1200 hours, it's unlikely that the mains are worn. The most likely culprit is the oil pressure relief valve-it maybe stuck open. I doubt whether the oil pump can be badly worn at 1200 hrs. It's possible that the oil pick up tube has an air leak or there is some blockage at the inlet of the oil pick up. I'm not familiar with the specifics of your engine but you can most likely access all this by removing the oil pan.

mostly_gas · Sep 17, 2015

Had similar problem with a 2 cylinder 1700. Changed oil problem quit for a few hours (5 or 10?) then back. Put pressure gauge on instead of light pressure would cycle between 10 psi and 70 psi. Changes oil again, pressure improved 20-50psi then one more oil change and it steadied out. Suspected the oil pressure relief valve was sticking from sludge, about 800 hrs at the time.

stevem5215 · Oct 11, 2015

So, following the advice listed I put a pressure gauge on it and the pressure is good at 60lbs at the low side and it shoots up to 80lbs when it's cold on the high side. Since then I put a t in the line and hooked up the light again and the light has been off since. Not sure what was going on there. Maybe sludge but I kinda doubt it as I replace the oil every year in it even though it's only used 50hrs a year.

Steve