Bizzare temp issue - Farmall H

Dan G · Aug 5, 2011

I have a 47 H with a bizzare temp issue. First, I don't know what normal op temp of an H is. I've always known gas engines to be 209, but this one runs at about 150 degrees. I can run it around all day and it's like , 150, 160. If I let it run on a down hill, and today was bad. I didn't notice it at first, but it was like 220. as soon as I move off the downhill posture it goes back to normal. This has been like this all summer. It may have been like that since I've owned it, but I never noticed it till now. It never overheated, and the radiator is new. Obviously, I checked the coolant level and it's normal.

If I let it run while pointed up hill on a hill, it's fine. Pointed down hill on a hill, and the temp goes up steadily. All I've done so far is just not let it run on a down hill too long. The temp may go past 220 if I let it that way, but I didn't want to find out.

I'm guessing perhaps a weak water pump? I've never seen a gas engine temp have issues with its uphill/downhill relation. Any ideas?

CNKS · Aug 5, 2011

This is stricly a guess. The temp sensor is in the top left rear of the block if I remember right. Sounds like you have something, what I have no idea, that allows the coolant to drain away from the sensor when going downhill. There is no load on the engine at that time, the temp should go down. Otherwise maybe the sensor has so much crud on it that it won't read right. You might take it out and look at it, provided you can remove it without breaking it. Your "level" temp is common for those engines. The edge of the red is the boiling point for the pressurized system, which I would guess to be 220 or so. I forget how much 7 or so lbs raises the boiling point. Antifreeze raises it too.

Pat-CT · Aug 5, 2011

This is also just a guess. Maybe if you have a blocked passage
somewhere the coolant is draining away from the sensor and its
reading an air pocket? If it were me I would just pull the sensor out
and give the system a good flush and see if that helps it.

Dan G · Aug 5, 2011

So you're guessing it's a sensor issue (IE the coolant isn't circulating by sensor while in a down hill position) ?

CNKS · Aug 5, 2011

Pat explained it better.

Jim Becker · Aug 5, 2011

Just a suggestion, point it down hill at the same angle required to get the evident overheating. Then pull the sensor as already suggested. If coolant starts to leak out as soon as you crack open the sensor retainer, the air bubble theory will seem less likely (not a guarantee as running/stopped may make a difference too.

Dan G · Aug 5, 2011

So it's not a larger issue like a leaking head or something? Just a sensor/circulation issue? I thought someone would chime in with..." I had the very same problem...." etc....I've never heard of such a thing before...It's like when I go to the doctor.."I've never seen this before..."

Dave S. · Aug 6, 2011

Mabe you need a new cover for the water jacket behind the carburetor. There are fins attached to the inside of it that direct the water flow to the rear cylinders. It could also have crud built up in the water jacket.

Tom Fleming · Aug 6, 2011

I the H thermosyphon or water pump? If thermosyphon, there is a simple answer: the thermosyphon works on gravity. If the nose is pointed down hill, the openings to the radiator are in the front, so the hotter coolant will be trapped at the rear of the engine to a certain degree, and hence you see the temp rise. Once you level out or go uphill, the coolant can circulate through the opens as designed. since you are rarely in a down-hill position for extended periods of time, I would not worry about it.

If you have a water pump and thermostat, then I am a bit perplexed.

my opinion.......
ps. just re-read your post, and saw you have a water pump. so, I'll let the above in place, but it doesn't apply to you situation.

John M · Aug 6, 2011

Let me guess, it has one of those cheapo parts-house gauges?? Probaly from Autozone or Advanced or somewhere like that. The gauge is the issue, youre not running hot or have flow issues or a dirty sytem or anything like that. Replace the gauge, top off the coolant and youll be fine.

Dan G · Aug 6, 2011

The guage came with the tractor. I don't know it's origin. Where's a good source for a NON cheapo one?

CNKS · Aug 6, 2011

On a similar note, I decided I wanted a temperature gauge on my Super A, needed or not I like gauges. I put it in the head outlet, which required a SC or SA1 outlet that I cut off to get to the right height. First thing I noticed is that the needle went into the red, then would come down -- I never associated it with up or down hills since in W Kansas there aren't very many -- but finally decided that it was not too hot after all. Never gave it a thought until the thread came up and you mentioned thermosyphon (H's always have water pumps). I think with thermosyphon the flow is not constant, thus the erratic readings.

John M · Aug 6, 2011

The cheap ones will work, Im not saying that. The ones at Autozone and such arent really made for tractors, with lots of vibrations, bumps and such, and arent made to be kept "outside" in the elements. I repalce all of mine with OEM type from whoever has them cheaper at the time I need one, but I do have one tractor with one from my local parts store, not a chain store, that was rated and approved for tracotr use. napa may have ones like that.

Bizzare temp issue - Farmall H

Dan G

Member

CNKS

Well-known Member

Pat-CT

Well-known Member

Dan G

Member

CNKS

Well-known Member

Jim Becker

Well-known Member

Dan G

Member

Dave S.

Member

Tom Fleming

Well-known Member

John M

Well-known Member

Dan G

Member

CNKS

Well-known Member

John M

Well-known Member

Similar threads