8N Overheating

I have an 8n that overheats inconsistently it does not have a shroud or thermostat this has been from day one of owning this tractor. I have replaced the water pump when I drained the radiator fluid drained with no problems I have pressure washed the radiator with a power washer still it heats up. When it does overheat there is no pressure when removing the radiator cap so it seems as the flow is not moving correctly. I have checked the dip stick it shows no sign of coolant in the oil. Ant help would be greatly appreciated! Thank you!
 
How full are you filling the radiator? it should be just over the core, not all the way to the top. How do you know it is overheating? have you checked the temperature? I would install a thermostat in in myself!
With it running, you should see moving collant.
The core tubes may have been become plugged over the years not allowing circulation of the coolant properly.
 
I know it is overheating because one it stops running and the
gas tank has a to of pressure in it from being so hot. When
this first started happening I drained the radiator the coolant
drained very fast when the bottom hose was removed I refilled
with fresh coolant just below the cap.
 
" I refilled with fresh coolant just below the cap. "

Uh-huh.

And that's why it's "over heating".

See tip # 24. And 35.

Re the t-stat, see tip # 25.
75 Tips
 
Just purchased a shroud and thermostat today will see if that works. I have been using this tractor for 15 years with no overheating before.
 
If your gas tank has pressure in it, it is not venting properly. The vent hole is probably plugged. Get a vented gas tank cap or drill a small hole in the one you have.
 
Mine overheated because there were holes in the radiator. The holes were high (the big one was at the neck), so coolant didn't leak out. But it couldn't hold pressure (obviously) so it boiled over at a lower temperature than it should. New radiator (and no other change) solved that. (I suppose it's possible that there could have also been plugging in the radiator.)

Missing a thermostat has absolutely nothing to do with overheating. The thermostat is important for engine wear as described in Bruce's tips. A thermostat makes an engine heat up to its operating temperature faster--it has nothing to do with cooling it off. A bad thermostat can lead to overheating, but a missing one will not.

-Paul
 
(quoted from post at 11:57:34 07/29/14) How full are you filling the radiator? it should be just over the core, not all the way to the top. How do you know it is overheating? have you checked the temperature? I would install a thermostat in in myself!
With it running, you should see moving collant.
The core tubes may have been become plugged over the years not allowing circulation of the coolant properly.

What he said. If the pump is ok and there is no thermostat to go bad and no leaks, then either the coolant channels are blocked (very unlikely) or the radiator core is blocked. I vote for the radiator.
 
2 different problems

fix the gas tank under pressure first.
Like said, vented cap or drilling a hole in it will solve that.
(stick a straw in a glass of water, put your finger over the end and pull it out. not much 'flow' right? won't run without gas flow.)

Meat thermometer will tell you your real temp if you don't have a gauge.
Since you don't run a thermostat, looking in the radiator when it's running should leave no doubt of flow.
It should be violent with a new pump.

IMO those shrouds are way more important than people think.
Lots are cut or removed.
Air will always take the path of least resistance.
no shroud, and air will sneak in from the sides,top,bottom,
rather than coming thru the radiator.

Caps.....unlike a car, an early tractor with the coolant just over
the fins properly...with a good cooling system...the cap could be in your pocket and it wouldn't make a difference
 

You're overfilling the radiator. Put in just enough fluid to cover the core. Let us know if that makes a difference.

Don't worry. It's a common error until you learn better. Now you know.
 
I am having a similar issue....

new 6 blade fan, new water pump, new radiator. New shroud on the way ( old one was incomplete and didn't fit the new radiator)


I consistently run into the "red" region of my temp gauge. although, the red region could be the correct temp, and the red region is red for a different type of vehicle/tractor
it looks similar to this http://www.ebay.com/itm/FORD-NAA-600-temperature-temp-gauge-NEW-for-tractor-/350974500568?pt=BI_Heavy_Equipment_Parts&hash=item51b7b5ded8
 
" although, the red region could be the correct temp"

Yep. And it probably is.

" ..... and the red region is red for a different type of vehicle/tractor"

If it really bothers you, why not get a gauge that has the actual temp displayed?

And, if it really is overheating, there are a few other things to consider.

Sometimes (rarely) the t-stat can migrate in the hose & get stuck closed. Or, in an attempt to keep that from happening, some owners will put a third clamp on the hose & tighten it too much resulting in a stuck t-stat. The OEM top hose came w/ a non-adjustable ban to keep the t-stat in place.

The fan belt should have 1/2" of flex at the mid-point; no more, no less.

Unless you have a pusher fan, blowing out the radiator from the engine side is always a good idea.

But, sometimes you just have to bite the bullet & flush out the block & radiator. To do that, remove the t-stat from the top hose. Then, remove the bottom hose from the radiator, stuff a rag in the bottom hose connection on the radiator & stick your garden hose in the top of the radiator. Turn the water on (reverse flush) & the water will flow into the radiator, then the block & out of the disconnected lower hose. Let it run until the water is clear. Then, check the radiator flow. Stick the hose in the top of the radiator; the water should flow out of the bottom w/o backing up in the filler neck. It should flow at 19.5 gallons a minute. As a final flush, put a gallon of white vinegar & about 2 gallons of water in the radiator, run it to operating temp & then drain it again. Don’t forget to put the t-stat back in correctly!

Use 50/50 anti-freeze & distilled water as your coolant. The anti-freeze contains rust inhibitors, pump lubricant & raises the boiling point of the coolant.
75 Tips
 
" All of the temp gauges that I have seen do not require an outside voltage. "

Same here. I've never seen one w/ an electrical sending unit.

But, there are lots of things I've never seen that are possible.

Like honest politicians, kind & caring x-wives, etc
75 Tips
 
(quoted from post at 16:19:10 07/31/14) All of the temp gauges that I have seen do not require an outside voltage.

gauge does not need voltage to run, just uses a capillary tube.

as far as the replacing the gauge, I would, but I can't justify 40 bucks on a gauge right now. It's just a cosmetic thing, and it doesn't matter that much anyway as long as the tractor isnt shooting water/coolant out of it.

looking forward to installing the shroud.

Should help a ton.
 
All righty then all you guys were right I lowered the coolant level and could see that with the new water pump she was flowing like Niagra Falls and no more over heating I have ordered a new shroud and thermostat as most of you recommended I should have it on over the weekend. I do appreciate all the help!!
 

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