Case 40xt Getting Hot After New Water Pump And Thermostat

[Dbchaplin]

I have a case 40xt (only 950 hrs) that had a very small leak out the weep hole in the water pump which the dealer said was an indication it was going bad. Went ahead and picked up a new thermostat while i had it apart since you have to drain the whole system and remove the radiator anyhow to get to it.

It never had any issues getting hot before, even with the slow drip out the weep hole. The temperature light had never come on and I've operated for about 70-80 hours over the last 9 months I've owned it. Now the last two times i've operated it since changing the pump and thermostat my temp light has come on. The first time I had been pulling honeysuckle/brush for a few hours and it came on. (Approximately 45-50 degrees outside).

Today, i was using my brush grapple cleaning up limbs from trees i pushed over with an excavator and cut for firewood and it came on in only about 30 mins. (its only 39 degrees out today). I immediately parked it in the shop and shut it down. The engine didn't feel that hot holding my bare hand over it and i could touch the side of the radiator for a couple seconds. It was hot but not enough to burn you.

I did notice two small trails of liquid in the dust on the belly pan on the right side directly below the radiator approximately straight down from the radiator cap but it was minimal and i didn't see it dripping off anything or pooled anywhere.

Any thoughts? I thought maybe my sensor was going bad but then that wouldn't explain the small trails of liquid in the dust below the radiator. Could the brand new Thermostat be sticking closed maybe? Or the radiator cap be going bad?

 

[Delmer]

Are you sure you got the air out of it? the level is correct.

If the thermostat is slow to open then the temps of the radiator will tell you what's going on, get an infrared temp gun and check the temp of the top and bottom of the radiator, and the inlet and outlet on the engine, while the engine temp light is ON.

 

[jacobd]

Overheating is relative. You need to know how hot it's really getting. Get a cheapo laser thermometer and take some readings before and after the alarm goes off. The hottest spot should be around the #4 cylinder and the thermostat housing should be around 180 degrees I believe.

 

[DIYDAVE]

Overheating is relative. You need to know how hot it's really getting. Get a cheapo laser thermometer and take some readings before and after the alarm goes off. The hottest spot should be around the #4 cylinder and the thermostat housing should be around 180 degrees I believe.

X2 on the laser thermometer, one of the cheapest, easiest to use diagnostic tools out there, usedta cost about $3-400 bucks, now down to $30!

Aint got the thermostat in upside down, do ya? If it is a bad t-stat, or you suspect it, you can use the laser t-meter, to see what temp it opens at, by observing, in a pot of heated water, on a cook top. Do this while wifey is gone, they don't like you usin the pots, pans, stove, to diagnose equip parts...

 

[Dbchaplin]

Thanks as always guys. I will pick up an infrared thermometer this week. I am going to replace the radiator cap for sure because i took it off this morning to check the coolant level in the radiator and when i put it back on it was leaking out the cap. I'm out of town this week for work so i will pick up a new cap and then check the temps. I've had cars and other equipment overheat in the past and this isn't doing any of that. Also, from my original post the two runs in the dust i mentioned came from the coolant tank, there is an overflow. I know that if that cap isn't holding proper pressure that can cause problems so hopefully that isn't the issue.

As far as the thermostat being upside down, im pretty sure I put the new one in exactly like the old one came out but I had a several projects going on at the same time and wouldn't that be a bugger if i made that silly mistake haha. I'll let ya'll know what i find but it probably won't be until next weekend.

 

[Dbchaplin]

Well gents.. I have some info to report and request some more troubleshooting assistance.

I bought an infrared thermometer. I went ahead and pulled the thermostat back out just to double check that it was installed the right way. The spring was facing the block and the jiggle pins were at 12 and 6 o'clock. I went ahead and installed the old thermostat just to eliminate the possibility that it was a faulty thermostat from the factory (I only replaced it because it was easier to do while i had the radiator out and the water pump was being changed).. Put it back together and problem remains the same. It does seem like the light is coming on much faster now.

The first time i ran the machine after changing the water pump and thermostat i ran for 2 hours or more pulling trees and brush before I noticed the light (im not sure if there was ever an oral tone or not, i don't recall there being one). The next time it came on after about 30 mins of moving brush piles into a pile i was burning. This time it started coming on within a minute or two of starting the machine. It comes on faint at first and then gets brighter. Once again no oral tones, just an illuminated light.

I ran the machine wide open with the radiator cap off to bleed the system after refilling it. I put a funnel in the radiator so it couldn't over flow and i got air out of the upper hose as it ran. I ran it for several minutes to warm up some and then ran full throttle for 12-15 minutes taking readings. It took 7-8 minutes for the radiator to even start feeling warm to the touch. The upper part of the radiator peaked at 176.9 degrees and stayed right around that temp for several minutes. The lower part of the radiator was right around 98-101 degrees. I took several readings of the engine but wasn't sure where to check so i focused on the block next to where the injectors thread into the head. The injector area closest to the front of the machine (maybe #4 cylinder?) was around 215-230 degrees while the others were around 190-200. (I'm not sure if there is a better place to take the reading). The exhaust manifold was reading around 350-375 where it comes off the engine block (seems low to me, but what do i know).

Any chance the sensor is going bad? I saw someone had hand written in the owners manual "Temperature sensor located in block" which leads me to believe that its been changed before. So I'm back to requesting troubleshooting assistance with this new information. The help is greatly appreciated.

 

[jacobd]

Those temp readings sound just right to me. I'd swap the sensor out.

 

[DIYDAVE]

Sounds like you're on the right track, and the sensor could be it. Readings look normal to me, farthest from the radiator will be warmest. If you have an injector running lean, the temp would show hot near that injector. Don't forget to take a close look at the wiring, going to the sensor, too...

 

[Delmer]

Was the engine temp light ON while those readings were taken?

 

[Dbchaplin]

Yes, the light was bright when I took those temperatures. It starts out dim and gets brighter but it was bright for sure when i took those temps.

I picked up a new sensor last night and will install it this week and check the wiring at the same time.

 

[Dbchaplin]

It seems as though the problem is solved with the new sensor. Ran it through 2-3 thermostat cycles and no light. Once again, sure appreciate everyone’s expertise on this forum!

 

[rondig]

Engine wont bleed with cap off....there is a petcock on intercooler if it is 4bt cummins