CAT299C - Overheating & NO cab heat

[HighFlyerAK]

Happy New Year fellow HeavyEquipment Members!

First things first!
Serial #CAT0299CJJSP00667
6,195.0hrs
I had a new cylinder head gasket replacement/repair done by the local CAT dealer in Februar of 2019.
I asked to look it over and take care of things which stand out and replace them at that point, rather than do the least necessary and then have to bring it back again.
I am 60 miles away from the next town, where the closest (and only) CAT dealer/repair is located.
$12,000 later, I got the machine back and was quite happy all summer, running my mulcher, some bucket work and occasionally moving things with my forks.
Over all, I spent about 40hrs running the machine in 2020.

Now - I needed to do some snow clearing last week and plugged my engine block heater in over night, started it up the next day and ran it for about 30-40min to let the hydraulic oil come up on temp as well.

As soon as I started moving the machine, the engine coolant temperature started to go hot.
If I would stop moving and let it run on idle, it would every so slowly come back down.
I had the beep, the yellow exclamation mark, come on. I shut it down and let it cool off.
Went into maintenance mode on the display to look at the temperatures, it got up to 224°F before I shut it down.

Also - I have absolutely NO CAB HEAT! Ice cold air, fan is going strong. But no matter what, I can’t get any temperature out of any of the air fins.
I did not run the heat since I got the machine back, until now.

SO!
I drove to town to talk to the dealer, they have no suggestions, other than bring it all the way to town and pay a ton of money on something what was just repaired. (just a a tiny lit frustrated - Sorry)

My buddy suggested a valve, a heater valve, which might have been forgotten to be turned back on when doing the work. CAT dealer said they don’t touch them when doing any work on the machines.
Problem is - I can’t find it to check myself!

Radiator cap was replace in summer of 2018.
Thermostat was replaced in summer of 2018.
Water pump is on order (just in case).
Water pump belt was lose, which I tightened, no change.
No error codes!
I searched through the (very expensive) maintenance manual, but no help there.

PLEASE - ANY ideas or help is greatly appreciated.

Thank you!

~Andreas

 

[Nige]

Did you check the coolant level.?

 

[HighFlyerAK]

Did you check the coolant level.?

Hallo Nige,

Yes, I did. coolant is visible in the little sight glass on the radiator and the overflow coolant reservoir is about one inch (give or take) above minimum level with the door open.

 

[Delmer]

I hope they didn't fill it with water, at a Cat dealer, in Alaska. But that makes as much sense as anything.

Heat is simple, hot water has to move to the heater core, and air has to go through the heater core. You have air moving, but you could have a blend door keeping the moving air from the heater, not sure how that is set up. Track the heater hoses with the engine cold/warm to see where they go, and if there's any valve visible on the engine, could still be one near the heater core. The with the engine hot, the hoses should both be hot, simple right?

With the engine as hot as you dare, and 220 won't hurt a thing if it's full of coolant and you're using it lightly, check the temperature of the thermostat housing going to the radiator and the water pump inlet coming back from the radiator. Post those temps and we'll have a better shot at guessing what's going on.

If it's full of coolant, not pure water/ice, then the water pump falling apart is the next best guess, the temps will tell the story.

 

[HighFlyerAK]

I hope they didn't fill it with water, at a Cat dealer, in Alaska. But that makes as much sense as anything.

Heat is simple, hot water has to move to the heater core, and air has to go through the heater core. You have air moving, but you could have a blend door keeping the moving air from the heater, not sure how that is set up. Track the heater hoses with the engine cold/warm to see where they go, and if there's any valve visible on the engine, could still be one near the heater core. The with the engine hot, the hoses should both be hot, simple right?

With the engine as hot as you dare, and 220 won't hurt a thing if it's full of coolant and you're using it lightly, check the temperature of the thermostat housing going to the radiator and the water pump inlet coming back from the radiator. Post those temps and we'll have a better shot at guessing what's going on.

If it's full of coolant, not pure water/ice, then the water pump falling apart is the next best guess, the temps will tell the story.

I agree - simple physics! But yet, I find myself freezing inside while the engine goes hot if I would let her.
I can’t really run the loader, since it only takes 30sec to one minute while moving/operating to go hot.
Coolant is a good red color, so I assume coolant was mixed/added properly. But I will check on coolant mixture.

I had it running today and believe the thermostat was slowly opening around 123°F... the return hose took some time before becoming warm. It got warmer/hot after I shot it down. But I won’t have hard numbers until I get my hands on a laser temp gun.

Thank you Delmer for your input/suggestions!

 

[Delmer]

You already have the water pump on the way, so not much to do but wait.

 

[HighFlyerAK]

You already have the water pump on the way, so not much to do but wait.

Perhaps I was hoping that someone here would exclude the water pump from being the cause for the symptoms and save myself $350.00 plus the work... But I guess it seems a possibility...

 

[Delmer]

I don't know how cold it was when you were overheating this thing, if it was above 20 then you can tell the coolant concentration close enough between your fingers, so that eliminates the heater core and radiator being frozen up. Nothing in the heater valve, core or anything else to do with the heater will cause the engine overheat, so ignore the heater issues.

For the engine to be full of the correct coolant and overheat in temps near freezing, either the air is blocked nearly completely, or the coolant flow is blocked nearly completely. If the coolant was flowing through that radiator with no air flow, then the return hose would be hot, the fact that it heated up after you shut it off means there wasn't much coolant circulation considering the temp. If the thermostat failed closed, you'd have excellent heat. It almost has to be the water pump, or a shop rag in a bad place, or more than one problem at the same time. Like a heater valve closed, and a failed thermostat or temp sender. The temperatures will tell all, or enough anyway.

 

[KSSS]

I am no mechanic, but I don't see how it could be anything but that. Thermostat works, heat in the cab does not work. The machine overheats in a minute. It appears its not moving any coolant. Assuming the belt isn't glazed so smooth that the belt is slipping on the pully, which I am sure you would notice, the shaft must be sheared off in the pump or something similar.

 

[Kiwi-truckwit]

Just thinking out loud, there couldn't have been some air trapped in the heater core that's moved now that you've started using the heat?

It could be just as simple as bleeding the cooling system again. Worth a shot, anyway.

 

[HighFlyerAK]

I don't know how cold it was when you were overheating this thing, if it was above 20 then you can tell the coolant concentration close enough between your fingers, so that eliminates the heater core and radiator being frozen up. Nothing in the heater valve, core or anything else to do with the heater will cause the engine overheat, so ignore the heater issues.

For the engine to be full of the correct coolant and overheat in temps near freezing, either the air is blocked nearly completely, or the coolant flow is blocked nearly completely. If the coolant was flowing through that radiator with no air flow, then the return hose would be hot, the fact that it heated up after you shut it off means there wasn't much coolant circulation considering the temp. If the thermostat failed closed, you'd have excellent heat. It almost has to be the water pump, or a shop rag in a bad place, or more than one problem at the same time. Like a heater valve closed, and a failed thermostat or temp sender. The temperatures will tell all, or enough anyway.

I hope air isn’t the issue, especially since it has been working flawless all summer. If it were the water pump, I would be happy and call it fixed.
I will keep the post up to date and come back with the final result, something I find missing on most post on all kind of trouble shooting forums.

 

[HighFlyerAK]

I am no mechanic, but I don't see how it could be anything but that. Thermostat works, heat in the cab does not work. The machine overheats in a minute. It appears its not moving any coolant. Assuming the belt isn't glazed so smooth that the belt is slipping on the pully, which I am sure you would notice, the shaft must be sheared off in the pump or something similar.

Like mentioned, I actually hope now that it is as simple as the water pump (fingers crossed)!

 

[Nige]

I’m going to suggest that you loosen the hose that connects the thermostat housing and the radiator at its highest point and see if you get any air at all out of it. TBH it won’t be the first time a remote coolant reservoir level has been at the full mark but the system itself has been basically empty.

Did you confirm temps with a non-contact thermometer just to be sure.?

I still have my fingers crossed that it’s the water pump though.

 

[HighFlyerAK]

I’m going to suggest that you loosen the hose that connects the thermostat housing and the radiator at its highest point and see if you get any air at all out of it. TBH it won’t be the first time a remote coolant reservoir level has been at the full mark but the system itself has been basically empty.

Did you confirm temps with a non-contact thermometer just to be sure.?

I still have my fingers crossed that it’s the water pump though.

I will get my hands on a non-contact temperature gun tomorrow, Saturday. And I can certainly test the ‘loosen hose’. What would be odd, since it was working perfect all summer. And ‘Yes’, fingers crossed it is just a simple water pump issue. That would be nice.
Thank you Nige!

 

[HighFlyerAK]

Just thinking out loud, there couldn't have been some air trapped in the heater core that's moved now that you've started using the heat?

It could be just as simple as bleeding the cooling system again. Worth a shot, anyway.

That does sound very plausible to be honest. I did not touch the cab heat until now (last week).
Only thing is, I would like to give CAT dealer mechanic the benefit of the doubt to not make such basic mistake.
I spoke with the mechanic when I picked up the machine and he was very thorough and took the time to talk with me about all the things he did. I left the machine at the shop for the entire winter. So there was literally no rush on working on it.

 

[Kiwi-truckwit]

That does sound very plausible to be honest. I did not touch the cab heat until now (last week).
Only thing is, I would like to give CAT dealer mechanic the benefit of the doubt to not make such basic mistake.
I spoke with the mechanic when I picked up the machine and he was very thorough and took the time to talk with me about all the things he did. I left the machine at the shop for the entire winter. So there was literally no rush on working on it.

Thorough or not, we all miss things at times, or sometimes things take us by surprise.
For the sake of a simple bleed of the cooling system to eliminate the possibility, it could save you spending money on what may be unnecessary parts.

 

[lantraxco]

Just FYI, thermostats do not open at 123 degrees. They open very near operating temperature, that is, 140, 160, 180, 195, etc. give or take I believe less than 5%

Yeah, I can see how the heater core could drain out and then trap air when the engine was refilled with coolant. Still seems like a reach, but an air bubble pushed out of the heater core and trapped below the thermostat might be possible. I've made it a habit for decades on any thermostat without an air bleeder manufactured into it , to drill about an 1/8" hole in the disk to eliminate the possibility of air lock. The Deere engines back in the day would do that, and without water to heat the wax pellet in the thermostat, would overheat without the thermostat opening. Ask me how I know, lol

 

[HighFlyerAK]

Just FYI, thermostats do not open at 123 degrees. They open very near operating temperature, that is, 140, 160, 180, 195, etc. give or take I believe less than 5%

Yeah, I can see how the heater core could drain out and then trap air when the engine was refilled with coolant. Still seems like a reach, but an air bubble pushed out of the heater core and trapped below the thermostat might be possible. I've made it a habit for decades on any thermostat without an air bleeder manufactured into it , to drill about an 1/8" hole in the disk to eliminate the possibility of air lock. The Deere engines back in the day would do that, and without water to heat the wax pellet in the thermostat, would overheat without the thermostat opening. Ask me how I know, lol

Here is what I did...
Put the screen in maintenance mode, Service mode 5 (don’t know for sure now) sub ‘page’ 1, which shows coolant temperature in °F;
Started it (showing 75°F) up after being plugged in for about 1hrs, went to the back and watched the temperature while holding/touching the large hose from the thermostat housing to the radiator and the large hose coming back from the engine (I assume) to the water pump/thermostat housing;
At around 124°, I believe I felt a noticeable increase in temperature in the large hose coming from the water pump/thermostat to the radiator;
Touching the thermostat housing seemed to confirm the increase in temperature;
There was definitely a very noticeable increase in temperature right around 180’ish °F;

As soon as I get my hands on a infrared/laser thermo gun, I will do more testing with more accurate numbers;

I do like the thought about the small hole, but believe that it might have one from the factory. Not sure though;

From everything I have read so far, trapped air and/or water pump seem to be the suspects...

I will try to make some headway tomorrow or Sunday... and will report back!

 

[HighFlyerAK]

UPDATE!
It‘s just after 1300 AK time and we have made some progress!

With the help of my very savvy heavy equipment buddy, one issue was solved. To my own embarrassment.
Turned out that the hose clamp on the large hose, going from the thermostat housing to the radiator, was ever so slight loose and allowed to drain the radiator pretty much dry.
To my defense, Today was the first time I actually saw red snow underneath the skid steer, which there was none before, and the sight glass was showing red coolant. Just turned out to be residue rather than actual fluid level.
Coolant is now @ correct level and has been tested to -45°F. Also topped off the coolant overflow reservoir.
We refilled the radiator and temperature tested, including running the service screen on the display.
Temperature came up to 155°F and stayed there pretty much for the 20min running.
Outside temperature has increased quite a bit, we have pretty comfy 28°F outside right now.
We left the engine running with the radiator cap off until about 125°F, then closed it.

CAB HEAT - NO!
Still ice cold and following the (roughly 1“) from the thermostat housing to the front, the temperature is about mid 70‘s and becomes mid 30‘s really quick, just about where it runs across the front of the engine towards the right side and down towards the bottom.
So...?!

Any bleeding necessary?
Any valves under there somewhere?
Could it be a bad temperature control switch in the cab?

I have not changed the water pump because of the constant temperature - But could it still be?!

 

[Nige]

You got a Serial Number.?
That machine will have either an electrical or mechanical valve in the heater circuit. Both types are known to fail.