8n overheating

[Charlie Musslewhite]

I have replaced head gasket, water pump and had the radiator cleaned. It is still overheating. After about 15 to 20 minutes at idle it will start to overheat. Any suggestions?

 

[HCooke]

What are the symptoms of overheating? Do you have a temp guage on it? I've got 8 of these tractors and I have never had one overheat. I want to know what to look for.

 

[Charlie Musslewhite]

Yes I have a temp gauge and when the temp goes over 190 deg I shut it down.

 

[Jess Pidlin]

Are you actualy getting [b:b89c50adda][i:b89c50adda]steam[/i:b89c50adda][/b:b89c50adda] from the radiator, or just water overflow? If it's just water, you are filling the radiator too full. Just cover the coils, n's don't like too much water.

Have a gooden...

Jess

 

[Ramrod]

The normal thermostst would be 180 degree, so why is 190 a shutdown temp? The water cooled system is not overheating until it get above the boiling point of the coolant, which is 212 degrees for water and much higher for 50/50 mix of water/antifreeze.

 

[Dell (WA)]

Charlie........iff'n you MISS-INSTALL yer upper radiator hoze thermostat, it will OVERHEAT innna'bout 10-15mins. Remember pointy end towards the radiator.

Don't fergitt, DO NOT OVERFILL the radiator or it will pizz out the overflow tube until the correct radiator water level is obtained.

ALWAYS use 50-50 anti-freeze. Water wetter is also a good addition. ........Dell

 

[Charlie Musslewhite]

I don't have a thermostat installed.

 

[Gramps in NM]

Recheck your belt for tension, about 1/2 in play. You say radiator cleaned. Was the inside just rodded out and cleaned or the fins washed out good. When I got my 8N the fins were so dirty there was no light to be seen. take a hose and spray it out anyway. Cover your electrical with plastic and you can spray from both directions.
Luck

 

[Ramrod]

Charlie, I'm thinking and hoping that you have just over filled your new radiator. It should be filled up so that it just barely covers the fins. Look inside the cap. If you have too much water in there, drain some out, or just let it run until it spits it out while you watch the temp stabilize. My NAA runs at 190 or higher when I mow in the heat, and has done so for several years. That won't hurt it.

 

[Dell (WA)]

Charlie......would it surprize you to learn 190* is NOT overheating???.......respectfully, Dell

 

[Charlie Musslewhite]

I took the radiator to a shop to be cleaned and I removed any grass and seeds from the outside with an air hose. The radiator is clean inside and out.

 

[Dell (WA)]

Charlie.......you NEED a thermostat. NO ARGUE!!!

Why? 'cuz it takes about 30mins to heat the 6qts of OIL to drive OFF natural contaminates of combustion. Otherwize you gitt SLUDGE in yer oilpan. It is natural to have steam leak out yer oilfiller cap untill all the contaminates have evaporated. ........Dell

 

[R Geiger]

First I would get a thermometer that I could stick in the radiator and compare that to your add on temp gage. second, i don't think that 190 degrees is overheating and third they were not meant to just idle all the time. does it cool down if you increase rpms
good luck

 

[Charlie Musslewhite]

I just went out and mowed in the pasture a while and stopped when temp went to 220 deg. No water coming out of the radiator when I stopped.

 

[Charlie Musslewhite]

I'll intall one nothing else has worked. Not having a thermostat would that make it overheat?

 

[Bruce (VA)]

Lets see........

You have a temp gauge which you do not need & a t-stat which you do need.

The most common reason for an N to “over heat” is over filling the radiator. Only add enough fluid to cover the core. (check out tip # 24, below as well as tips 25 & 35) It is not actually over heating; it is just spewing out the excess water.

If the radiator is not overfilled, check for low coolant, a loose fan belt, debris in the radiator fins or a stuck thermostat. A bad water pump will usually squeak or leak.

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

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.

190* is not a reason to shut the engine off.
50 Tips

 

[Charlie Musslewhite]

I just finished mowing in the pasture and the temp was up to 220 deg when I stopped. I've never had an overheating problem before and I have cleaned or replaced everything to do with cooling. I will get a thermostat and hopefully that will help.

 

[Jess Pidlin]

[i:8d0b29c19c]"temp went to 220 deg. No water coming out of the radiator "[/i:8d0b29c19c]Are you sure your gauge is accurate? Check with a cooking thermometer.

Jess

 

[HCooke]

Installing a thermostadt will not make it run cooler. It will make it warm up sooner, which is a good thing. 190 deg is not overheating.

 

[HCooke]

Water, or a 50-50 mix of water and antifreeze? A mixture will be cooler than plain water.

 

[Charlie Musslewhite]

Yes a 50-50 mix of water and antifreeze is in the radiator.

 

[Charlie Musslewhite]

It would not suprise me but after mowing a while the temp goes up over 220 deg. I have a mix of 50-50 antifreez & water, radiator not over filled, replaced water pump, head gasket and had the radiator cleaned. I'm not sure what to try next. Any suggestions?

 

[wickedsix]

Maybe the gauge is off?

 

[Ramrod]

Charlie, does the temp stabilize at 220 or so? If it was truly overheating, it would continue to rise until it boiled out all the coolant. Is the coolant level still the same as before you mowed?

 

[Hobo,NC]

Good for you ,,, one of the lucky ones that has a temp gauge,,, so until its proven wrong you gotta believe it... Folks that don't have it are the only folks that figger its not needed..

220 is were I get a little nerves on a Flathead... Coolant absorbs heat so the more the better,,, the statements I have read that to much coolant will make it heat are,,, New'n on me,,, let them splain it
:lol: ,,, so once the coolant adsorbs the heat its gotta B circulated,,, air takes the heat away,,, so you gotta have a fan that will flow air thru the rad,,, loose belt, worn belt,, wrong belt come to mind,,, I would thigh'n it up and for-go the 1/2" what ever spec.

Must B hot were you live,,, if its that hot now then for sure you will need a fully functional fan shroud,,, not a hacked up one...

 

[Charlie Musslewhite]

The temp will go beyond 220 deg but the coolant level is still the same. It doesn't blow out the radiator.

 

[Ramrod]

OK, a couple of things came to mind on the drive in this morning Charlie. You said early on that you had no over heating issues before you did the head gasket, water pump, and radiator, so I am not going to look deeper than that right now.

An easy observation is to check the coolant flow. Leave out the thermostat for this test, and just fill the radiator up so you can see the coolant level over the core, and start it up with the radiator cap off. If there is no thermostat, you can look in there and see a lot of movement in the coolant. The new water pump should be pulling coolant off the top of the engine and ejecting it into the radiator via the upper radiator hose. If there is a thermostat, you will have to wait until the coolant warms up and the thermostat opens allowing flow through the upper radiator hose.

Now, if you see a bunch of flow, change the temp gauge, or at least use mama's cooking thermometer to compare readings and certify that your temp gauge is correct. If you don't see a bunch of flow, and I do mean a BUNCH, we have a problem. Either the water pump impeller is slipping on the shaft (very common) or the pump is broken or clogged. The other thing that comes to mind is maybe the wrong head gasket is installed which is blocking some of the water flow, which is a long shot on a flat head, as I am not even sure if that applies. I'm an overhead valve kinda guy (NAA).

I am not sure if I saw that you back flushed the block while you had it apart. If not open upper and lower radiator hoses (from the radiator DUH)and stick a hose in the lower, seal it up with rags, and blast away with full water pressure watching what comes out the upper hose, then reverse the hose and blast away in the opposite direction. Do this until the water runs clear.

I hate cooling system problems...

 

[Charlie Musslewhite]

I had an overheating problem before I changed the water pump,radiator cleaned, and installed new temp gauge. I back flushed the block when I had it apart. I can see water flow in the radiator so the pump should be working. I don't know what else to try. I appreciate any suggestions.

 

[Ramrod]

Let's talk fan and shroud. I have a six blade fan and a good shroud keeping my NAA cool in HOT Texas summers. It will get up there, especially while bush hogging and the radiator gets full of chaff, but never boils.

How's your fan and shroud?

 

[Charlie Musslewhite]

I don't have a shroud or a 6 blade fan. I've had this tractor since 1992 and never had an overheating problem until this year. The shroud and a 6 blade fan might work but I think I may have a bigger problem although the tractor runs good.

 

[Hobo,NC]

(quoted from post at 14:55:00 12/10/10) I don't have a shroud or a 6 blade fan. I've had this tractor since 1992 and never had an overheating problem until this year. The shroud and a 6 blade fan might work but I think I may have a bigger problem although the tractor runs good.

In the real world folks start eliminating possibility's,,, install a shroud,,, its a possibility's...

Out of all you have posted this is the only thing that looks like it would help,,, If it helps your tractor sounds just like my shroud-less tractor,,, that's why I have a temp gauge,,, its to keep a eye on it,,, it also lets me know the otherwise unknown,,, I am not as brave and ***** as folks that believe the un-know will not kill their tractor....

 

[Ramrod]

Charlie, when the tractor is hot, up to 220, see if you can get the radiator cap off safely, BE CAREFUL, it might boil over when you pop it, and look in there for a good flow, and see if you see bubbles in the coolant. It's a long shot, but could exhaust gas be leaking into the coolant?

AND, when you changed the gauge, did you also change the sender? Might also be worthwhile to make sure the sender is immersed in coolant by removing it and flushing the hole out.

 

[Charlie Musslewhite]

Thanks I will check water flow for bubbles in the coolant. I changed the sender when I changed the gauge. I'm not sure what to do if exhaust is leaking into coolant.

 

[Hobo,NC]

(quoted from post at 16:31:59 12/10/10) Thanks I will check water flow for bubbles in the coolant. I changed the sender when I changed the gauge. I'm not sure what to do if exhaust is leaking into coolant.

Answer this,,, when it runs up to 220 what do you do to get the temp back down to lets say 190/195....

What I do,,, I stop and leave the throttle at WOT,,, take a look at the front of the rad for restrictions... in a min. are so the temp will come back down,,, I know what it is tell'n me do you...