T0-30 Running hot under load

[NateMack]

Looking for help on my Ferguson TO-30.

Problem statement: Tractor temp gauge slowly approaches the "red band" when tractor is under load (cutting tall grass or pulling a disc)

History: 3 years ago I snapped the crank shaft right in the middle. Took the block to the machine shop to have it checked out, ended up having the shop go through it and rebuild to bottom end, new crank, bearing etc. Then I finished a full overhaul on the engine. When putting it back together I installed a temp gauge to keep an eye on things, didn t want to destroy my investment. Previously it had no temp gauge. This tractor gets limited to use since it a bit small for most farm jobs but I try to use it when it makes sense. Also its been handed down in the family since the 70s so its worth driving for that if nothing else.

Ever since the engine rebuild the tractor will always creep up into the "red band" on the gauge if doing real work, just driving around or short jobs doesn t have any issues. I ve recently taken some actions to try to address this and took a bit of the "kitchen sink" approach. New water pump and upgraded the fan from a 4 blade to a 6 blade. A note on the water pump I took some measurements of the impeller and the old and new measured almost identical, is also did not appear pitted or worn, I don t think this was the issue. The radiators not that old, it got replaced around the time of the engine overhaul since the old one was leaking. The radiator shroud is in place and I am getting good air flow through it. The radiator cap is a 9 psi lift, I believe stock is 7 psi, but I ve never gotten boil over so I don t think that s relevant.

Recent observations:

Driving around last night I decided to take some temp measurements with an infrared thermometer to see if my gauge is way off or not. With the needle in the middle of the gauge I measured 155F at the top of the radiator and 140F at the bottom of the radiator. Seems to me the gage is working as I would expect 180F+ to be the start of the "red band". Also for the troubleshooting process I have the thermostat removed from the upper radiator hose. I would expect this would result in the tractor not heating up much at all. Also I m in Michigan so outside temps are in the 60s not real hot here.

My best guess is I m having an issue with flow rate through the system, at 15-degree delta between the top and bottom of the radiator seems excess to me but I m no expert, seems to me that with more coolant flow I would have less of temperature between top and bottom and it would prevent a no T-stat engine from getting into the green band on temp.

So my question, is there a way to gain confidence that im getting good flow through the system? I assume radiator flow is inlet on the top and outlet on the bottom, can anyone verify? Should the tractor be heating up much at all without a thermostat, to me this is unexpected? Anything else I can investigate? I ve replaced every component and not solved the problem so I can't shoot any ideas down.


Tuck Away Acres Farm
New Era, MI

This post was edited by NateMack on 05/24/2023 at 05:30 am.

 

[Hdonly]

Running an engine without a thermostat is not a good idea. Without the slight restriction of the thermostat (even when fully open) can let the coolant move too fast and not absorb the engine heat and can also allow air bubbles to trap in places inside the engine cooling passageways. The thermostat does not control how hot the coolant gets, it only controls how fast an engine reaches operating temperature..
 

[NateMack]

Ok i'll keep that in mind and get the t-stat back in the system. Do you think not having a t-stat is causing my red band issue?
 

[jhwis]

Is it possible the fan pulley belt groove
is worn enough that the belt is riding too
deep thus not spinning fan/water pump fast
fast enough. I assume the belt is tight.
You blew out radiator fins with air or
water?
 

[Hdonly]

[Jim.ME]

Along with blowing out and ensuring the radiator fins are clear externally, and the other checks suggested. Check the temperature at the point where your temperature gauge sender is located. That will give an idea of what the temp really is when it "approaches the red band", it might not be as hot as you think. The gauge could be losing scale.

Have you set the timing by the book with a timing light?

What happens if you richen the load jet just a bit?

On a side note. You say: "I ve replaced every component and not solved the problem so I can shoot any ideas down." This sounds like you are ready to say it won't work, to any suggestions that might lead to an answer. Or did you mean to say, you have replaced many components and are open to suggestions?

This post was edited by Jim.ME on 05/24/2023 at 03:51 am.

 

[NateMack]

[NateMack]

[NateMack]

[NateMack]

Duplicate post - deleted

This post was edited by NateMack on 05/24/2023 at 05:44 am.

 

[LarryMaine]

Here's my two cents. A newly fully re-built engine is tighter than a well used engine. When I rebuilt my Ford 850, the engine would stall out at the speed it used to idle at comfortably. it now idles at about 50 rpm higher than it used to. Once the new engine is broken in, it will be able to idle at the older slower speed. This tighter engine can generate more friction and thus heat until broken in. Also, when your TO-30 is under load and is getting hotter than you are used to, what also happens to the oil pressure, does the oil pressure decrease at the same time? The issue may resolve itself as the engine gets broken in, as mine did. Again, just my two cents. Best of Luck, Larry.
 

[Jim.ME]

[sunbeam]

With your temp probe check different sides of the radiator for uneven temps for a parcel plog.
 

[Jerry/MT]

Driving around last night I decided to take some temp measurements with an infrared thermometer to see if my gauge
is way off or not. With the needle in the middle of the gauge I measured 155F at the top of the radiator and 140F at
the bottom of the radiator. Seems to me the gage is working as I would expect 180F+ to be the start of the red
band. Also for the troubleshooting process I have the thermostat removed from the upper radiator hose. I would
expect this would result in the tractor not heating up much at all. Also I m in Michigan so outside temps are in the
60s not real hot here.
My best guess is I m having an issue with flow rate through the system, at 15-degree delta between the top and
bottom of the radiator seems excess to me but I m no expert, seems to me that with more coolant flow I would have
less of temperature between top and bottom and it would prevent a no T-stat engine from getting into the green band
on temp.

If you have a normal TO-30 type temp gauge, it's a capillary gauge. The gauge fluid expands in response to heat at a
bulb located in the gooseneck that discharges coolant to the radiator. This gooseneck is in a metal casting and so r>measuring the temperature there will be within a few degrees of the coolant temperature when the engine reaches its steady state temperature. The top of the radiator is also metal so the temperature at the gooseneck should be within
a few degrees of the metal top of the radiator. The normal thermostat IIRC is 180F which means it should begin to
open at 180 F. Since you have it out. put it in a pan of water and heat it up, measuring the water temperature and
see if it begins to open when the water temperature reaches 180 F. If it does, you know your thermostat is working
correctly and you should re-install it. Now remove the pressure cap and start the engine and bring it to operating
temperature. Observe through the radiator filler tube and when you see fluid begin to enter the radiator from the
engine, measure the temperature of the coolant and note your temperature gauge position. Use the infrared
thermometer to verify the temperature, also. You should measure near 180F and the location of the gauge needle at
that point is indicating 180F. Mark that position with a grease pencil or a Sharpie. Replace the pressure cap.

Now do some work that causes the needle of the temp gauge to move to a higher level. Take out your infra red
thermometer and measure the temperature at the gooseneck and record that number as well as the needle position. Now
work the snot out of the tractor and repeat the measurement and record the position of the needle as well as the
infra red measured temperature. These numbers will help you calibrate the gauge. Now you can answer the question of
are you running hot.

I sold my TO-30 five years ago but I seemed to remember there was a quoted red line temperature in the Ferguson
Service Manual (If you don't have one you should get one.) of 234F with a 7 psi cap. I believe that's the boiling
point where heat transfer severely decreases. With a 9 psi cap that temperature would be higher.

There are a lot of reasons why engines overheat and you have covered fuel/air mixture, timing, belt slippage, pump pulley diameter differences,
impeller erosion, plugged rad air side but you haven't covered lower rad hose collapse with high engine rpms,
plugged coolant side passages, leaky pressure cap, for example.

Most lower rad hoses have a coil of wire in them to prevent pump suction from collapsing the hose at high flow rates
(read rpm). Plugged coolant side passages is obvious. Leaky pressure cap will lower coolant pressure that can lead
to coolant boiling with its attendant reduction in heat transfer rates.

Just some suggestions that you look into. I dislike color band gauges. If I had my way they would not exist only
numbered gauges would be used with a red line to indicate max allowable operating temperature. I think you will
find that you are being mislead by your gauge.