941 Overheating Issue after 1 hour of use

How is the timing of the engine? To see if the water pump is working use a temp gun to see if the water in is cooler that the leaving the head. Did it overheat before you worked on it? With the temp gun you can also see how the rad is working. Will it overheat if you just drive it around with out working the engine? Heating can be caused by many things all added together...WA7OPY

I'm not familiar with this Machine, but I'm sure it holds several gallons of coolant. Even an automobile with only 3 gallons of capacity in its coolant system may run for 10 or 15 minutes with a closed thermostat before temps climb.

If it were me I would verify the coolant is circulating. Easy and free. Then verify your temp gauge with a thermometer in your radiator opening while you are verifying circulation. Free and easy.

Is you cooling fan installed correctly ? Free and easy to check - pretty easy to fix if it's wrong.

I would not keep getting it to 255F. Find out the normal operating temp and don't exceed that.

Best of luck !

Hi, Cptcrnch1.
Are you looking at the water temp. gauge or the torque converter/trans temp. gauge? If my memory serves me rightly, all the 941s I have ever been on only went up to 220 on the water temp.gauge. Again, IIRC, many 941s only had color coded water temp gauges. I think the trans. temp. gauges go to 275 degrees F.

A kew-ree-yuss mind would like to know.

Just my 0.02.

on my 941b the transmission temperature rises well before the engine temperature

Ok its steaming out the filler cap but is it actually boiling and pushing out coolant? I expect it to boil dramatically long before it reaches 250.

I would start by confirming temperature on engine coolant gauge. When thermostat opens up a thermometer stuck in radiator neck should read about 170-180 degrees F. You can also use the infrared "temperature gun" type thermometer to check temp externally. Start at thermostat housing and upper radiator inlet and compare with lower radiator connection and report back.

Sounds like you have spent a lot of time cleaning the fins but can you shine a bright light through the radiator and see that it is clean. I have seen them cleaned repeatedly (but incompletely) and be plugged so there is no airflow. Any oil coolers stacked in front of the radiator core can trap debris between the two and really make it hard to clean effectively.

The second part of airflow is the performance of the fan. One common problem is having a fan blade installed backwards. Just flipping the whole thing around does not change a pusher to a puller, it takes a different blade assembly or one that the paddles actually pull out and rotate about 60 degrees to drop into a different notch. If someone installs the blade assembly backwards, the "humped" side of the paddles will be toward the discharge side of the fan instead of the "cupped" side. A fan installed backwards makes more noise and moves a lot less air. Your belt tension sounds about right to me but I am unfamiliar with the arrangement on your machine so I will defer to others more familiar.

Having worked up the external side of the problem, you may have scale/lime coating the inside of the radiator and plugging the flues so that even with good airflow over the outside , heat transfer is impeded. This can be hard to diagnose but temp readings with an infrared gun can pick it up. If it's plugged up internally, a professional cleaning is usually required though sometimes a flush with a heavy duty cleaner will help. The older type radiators with the core bolted to the tanks can be serviced on site if there is good access to the bolts holding the top tank on. I usually run a flush with diluted muriatic acid through before taking the top off and rodding the flues to complete the cleaning.

Good luck

The 941 has a transmission cooled by a water heat exchange system, the 941B has a fan blown oil cooler with a reduced engine cooling system, the item that creates the heat in the transmission is the Torque, the cooling system from it needs to be defined by a Serial No or a better description of the equipment. tctractors.

Hi Guys,
thanks for all the great input. You all have certainly given me things to check out.

I'm pretty sure based on what folks have said, I've incorrectly misread the transmission temp gauge as my engine temp gauge, but that being said I dont think I have just a engine temp gauge from what i can tell....I dont recall any just simple gauges that are color coded (no numbers) that have a temp symbol on them. seems odd, but maybe I've overlooked it. I'll look much closer this w/e. I'm going to try and trace the wire from the back of the numbered temp gauge that I think is now the trans. temp gauge to see where it goes.

I'm got a laser temp gun to look at temps thru out the engine....pre and post thermostat hose, top and bottom hose of the radiator etc. (I'll report back after the weekend). I've also got based on some folks input a new thermostat and pressure cap for radiator. I'll also check the fan direction and strength. I can say based on what folks have said, my fan belt is loose. how to tighten? tensioner? i did notice I've only got 1 fan belt, but a place for two...could that cause an issue? I thought the 2nd belt was mostly so you wouldnt get stuck if your only one broke.

I'm thinking the above will give me a jump on the radiator portion of my issue, but now if I'm thinking of this correctly, I might also have a transmission temp issue bc of either a torque issue or possibly a low trans. fluid level or how the transmission heat exchange works.

So starting w/ the basics, (pls excuse the naivety of this ?)....where on this machine can you check the level of transmission fluid?
(I've found that this machine has had low fluid levels in everything else I've checked/replaced so far, so fingers crossed, maybe it has just low transm. levels too)

I have a 941 machine with a D330C engine....which I believe from what Ive read, has a transmission cooled by a water heat exchange system (my serial # 80H1666) and I dont see an oil cooler near the front fan, which I believe was for the 941😎 ....could there be a clog in this heat exchange system? where to check? is there a place I can temp test btwn two points w/ laser temp gun to see?

Does the radiator fluid exchange heat w/ the transmission fluid to cool the trans fluid as the name implies? If so, could the high temp radiator fluid be causing the transmission fluid to overheat as it exchanges or am I thinking of this wrong? Or visaversa, could an extremely hot transmission fluid be causing the radiator fluid to superheat? are either of these even possible?

Thanks for any input and education on these questions. I'd like to think I didnt get in over my head w/ this machine but I'm beginning to wonder! 😉
Much appreciate the everyones help (and patience w/ my ?'s!)
Pls advise and I'll check back in shortly.
cheers!
JR

Its easy to see which temp gauge you are looking at, the transmission gauge has a gear shape on the face while the water temp has a teardrop shape, I'm not sure if your machine should have a colour coded gauge to match the water pressure gauge. It was about this time that Cat stopped using water pressure gauges on some machines and it may have only three colours on the temp gauge. white, green and red.
The transmission cooler is on the left side of engine and mounted vertically alongside the oil filter, you will see the two oil lines going in and out of it, sit on the centre brake engine flat out in top gear and watch the temp rise, before the trans temp hits the red, go back to neutral, leave it at high idle park brake on, then check the temp of those two lines going to the transmission cooler, see what the difference is with your infra red gun. Also check how fast the transmission temp drops down, it should be quite fast.