Poor cab heat

[Cidertom]

Couple of ideas:
Mow a patch of thistle that has gone to seed. This plugs up the side screens, the radiator screen, the radiator and your lungs. I could not keep the front clean enough on the 4520 to keep the engine heat at "reasonable". It sort of looked like I was mowing in a snow storm.

Slightly more practical:
On a radar site I was on, we had a "coat" built of canvas for the tug tractor we used to move shelters. Covered all of the hood. Otherwise it never would heat up enough to run well. An awning shop should be able to come up with a green blanket to keep the deere warm.

 

[Willl]

When they tested the thermostat in "hot" water, was a thermometer used to tell exactly the temp it did open at ?
Guessing won't do.

Is the heater hose tapped into the system just before the thermostat like most cars/trucks ?

 

[Chris_VA]

Just came across this post and thought I'd chime in since I have a 3720 cab. Now keep in mind I haven't used the heat since last winter, but when I did, it worked fine. It would run me out of the cab on anything but low fan and the mid setting on the temp control. I only have to run the A/C at night to minimize fogging. During the day, I don't have a problem. Even with the A/C on, I don't have to adjust the heat temp. It just flat heats. Cools good in the summer also. I'm interested in the comments about this being a known issue with Deere. Lets hope not but please keep us informed of the process.

Thanks,
Chris

 

[radman1]

When they tested the thermostat in "hot" water, was a thermometer used to tell exactly the temp it did open at ?
Guessing won't do.

Is the heater hose tapped into the system just before the thermostat like most cars/trucks ?

Yes, he said he checked it with a thermometer. He said the thermostat opened/closed at 154-156F. I don't think the thermostat is the issue since JD tech support acknowledges this is a problem and engineers are trying to get a fix on it. JD tech support told them, the engine was designed to put out much more hp than want it is set up for. The cooling system was designed on more maximum hp. The radiator just seems to large for the small engine.
The heater hose comes directly off of the water pump like a car. After circulating through the cab heater, it returns to bottom radiator hose on the right side.
Local dealer also checked the relay/shutoff control in the cab heater and it is working properly. It seems as though all the bases have been cover by my dealer. Service manager called area rep today. Rep said if Jd support doesn't call back by monday am, he will call and try to get some answers. Jd support was suppose to call back today.

 

[radman1]

Just came across this post and thought I'd chime in since I have a 3720 cab. Now keep in mind I haven't used the heat since last winter, but when I did, it worked fine. It would run me out of the cab on anything but low fan and the mid setting on the temp control. I only have to run the A/C at night to minimize fogging. During the day, I don't have a problem. Even with the A/C on, I don't have to adjust the heat temp. It just flat heats. Cools good in the summer also. I'm interested in the comments about this being a known issue with Deere. Lets hope not but please keep us informed of the process.

Thanks,
Chris

That is the puzzling part to me. Why does this seem to be a problem now when others claim to have no problem on older cab tractors which have been used in the previous winter? I have to wonder if JD made some changes to the cooling system. I also wonder if the noncab 3000 and 4000 twenty series have the same problem but it is not noticed by the owners since cab heat is not needed. I would have to guess that the same radiator and cooling system is used in all the them regardless of cab or no cab.

 

[radman1]

Brought tractor home tonight. After 5 days at the dealer, I have a nice new piece of cardboard in front of the radiator and still no cab heat. I don't blame the dealer. Dealer was initially a little slow to acknowledge a problem but now has been very upfront and has checked out nearly all reasonable possibilities. (After a little prodding from me ). I'm not a mechanic but have been around farming and tractors most of my life and I know a skunk when I smell one. Now up to JD corp to get a solution.
I remember many years ago, using a can of gravel filled with a little kerosene and lit to make heat in the winter on our combine cab. Hope JD corp doesn't read this part to come up with a similar solution.

 

[dirtworksequip]

radman,it is supposed to get down in the 30's this weekend. I'll make it a special point to try out the heater on my 3520. Whats the serial number on your tractor?

 

[radman1]

radman,it is supposed to get down in the 30's this weekend. I'll make it a special point to try out the heater on my 3520. Whats the serial number on your tractor?

LV3720H281500

Radman1

 

[minimax]

The serial number on mine is LV3720H281451 and the heat works great????

minimax

 

[radman1]

The serial number on mine is LV3720H281451 and the heat works great????

minimax

Where are you located? Have you tried the cab heat when it was cool/cold outside? Your serial number is very close to mine.

 

[Kyle_in_Tex]

156F seems cold to me for a thermostat but here's my 2 cents.

If the thermostat blocks the system like it should, the engine will get hot. If the thermostat lets too much flow thru or sticks open and the radiator is oversize, yes, the coolant will never get up to temp. I put a "high performance" thermostat in my 350 Suburban and now when you watch the temp gage it, it goes up and down about 20 degrees. This is due to the high flow rate which cools the engine too quickly when re-opening.

Did the service guy say 156F was correct? Some thermostats will adjust between wide open and shut slowly to effectively manage the coolant temp. When testing the thermostat, did it all of a sudden "pop open"? Did you try a new one to see if it got better?

 

[dirtworksequip]

radman, it's probably ser# 1500 and up. Only kidding. Hope you are able to figure out what the problem is. Tried heat out tonight on my 3520, worked fine.Actually got too warm. Ambient temp. 40 degrees.

 

[minimax]

I live in northwest washington state about a hour from canada,in has been in the high 30's and low 40's and the heat works fine,good luck.

 

[radman1]

156F seems cold to me for a thermostat but here's my 2 cents.

If the thermostat blocks the system like it should, the engine will get hot. If the thermostat lets too much flow thru or sticks open and the radiator is oversize, yes, the coolant will never get up to temp. I put a "high performance" thermostat in my 350 Suburban and now when you watch the temp gage it, it goes up and down about 20 degrees. This is due to the high flow rate which cools the engine too quickly when re-opening.

Did the service guy say 156F was correct? Some thermostats will adjust between wide open and shut slowly to effectively manage the coolant temp. When testing the thermostat, did it all of a sudden "pop open"? Did you try a new one to see if it got better?

Yes, he said that thermostat temp was correct according to JD. Didn't ask him how fast it opened. Like you said, 156 seems cool to me also. I think the radiator is just too big. Even with the radiator completely blocked off the engine block temp only reached 125F.

 

[Willl]

Even with the radiator completely blocked off the engine block temp only reached 125F.

This makes no sense to me.

At 125F, that thermostat should be closed and no coolant flow till it reached 156F, or there abouts.

I'm curious as to what temp it would reach without the fan belt on !!!!

 

[turbo36]

I got a new 3720 Cab about a month so after reading this thread I got concerned about the cab heat. I ran a little test this weekend to see how mine worked.

Outside temp 46 degrees

Test #1.
Ran tractor at 1,500 Rpm for about 20 minutes, the temp Gage moved 7/16" from the left, with the blower on high the cab temp was 92 degrees the air coming out of the vents was 105 - 108 degrees.

Test #2.
Ran the tractor at 2,600 Rpm for about 20 minutes more, the temp gage moved to 5/8" from the left, with the blower on high the cab temp was 108-112 degrees, the air coming out of the vents was 124-126 degrees.

Test #3.
2,600 Rpm, blower on low, cab temp 88 degrees

 

[radman1]

Turbo 36
Was it sunny out side or cloudy. I tried mine at night and didn't workd the tractor hard and got poor heating. Also were you working the tractor hard when you did he tests or just at engine speed? 124-126F would be great. I seem to be alone in this problem. Used tractor today about 2 hours and cloudy, mostly light tasks. Temp gauge did get a little higher but outside temp was about 50. I was no where near 125 vent temp when I tried it.
Will see what dealer/JD has to say tomorrow.

 

[Kyle_in_Tex]

Yes, he said that thermostat temp was correct according to JD. Didn't ask him how fast it opened. Like you said, 156 seems cool to me also. I think the radiator is just too big. Even with the radiator completely blocked off the engine block temp only reached 125F.

Will is right, the thermostat should not open until its specified temp. Even if your radiator is as big as a barn. Your block should get up to temp before it opens.

I checked my JD manual for my 4310 and it says the stat should start to open at 157-163F and should be fully open at 185F. Your block should get up to 157F minumum.

I recommend an infrared laser pointer temp gun. You can get a good one for less than $100. You can point it at both sides of your waterpump to compare. They have numerous uses.

 

[turbo36]

Turbo 36
Was it sunny out side or cloudy. I tried mine at night and didn't workd the tractor hard and got poor heating. Also were you working the tractor hard when you did he tests or just at engine speed? 124-126F would be great. I seem to be alone in this problem. Used tractor today about 2 hours and cloudy, mostly light tasks. Temp gauge did get a little higher but outside temp was about 50. I was no where near 125 vent temp when I tried it.
Will see what dealer/JD has to say tomorrow.

Mostly cloudy and the tractor was at rest so it wasn't under load.

 

[minimax]

I don't thing the thermostat is bad because the engine is not getting hot enough.I'm starting to think it is a fueling prob.because the engine is not makeing much engine heat,of something like the wrong oil or something to reduce frictirson = less engine heat which = less cab heat.My 3720 runs at about a 1/8 of a inch below half on the water temp.,only takes 5 mins to get to temp.I don't know if that makes cense but good luck.

minimax