Yes. The sensor bulb is known to break off in the earlier models. It is probably up against the water pump. If you remove the pump you should be able to retrieve it.
Just to make sure I understand, your talking about the smaller part of the thermostat? I'll pull the water pump in the next day or two and post what I find.
Yes, the little copper brass bulb that hangs off the bottom. It has since been updated. You may be able to fish it out through the thermostat opening, but being non magnetic makes it a bit of a challenge.
Ok, just wanted to make sure. I have a bore scope I'm gonna look in the area first before trying the water pump, I figure its worth a shot. Thanks for the info.
If you can't find it, post back, we can suggest ways to flush it out. Was the engine running when you took those temps? I'd suspect the water pump wasn't doing anything with those temps. If the engine was off I suppose it's possible. Normally, I'd take the temps running, but it looks like you found the issue and if the water pump looks good and is tight, hopefully you won't have any more problems.
I used the bore scope, but couldn't see it. I thought about trying to flush it out, but it's a good reason to also check out the water pump. It's been replaced at some time. How bad are these for the impeller coming loose? I've got several dt466 internationals that seem to be bad for that.
Rarely an issue. Usually an external leak from overtightened belts. Rarely a problem in excavators.
I pulled the water pump, it was getting dark, didn't have my glasses, think I saw a small object fall out, but couldn't find it on the ground ( bottom covers removed for cleaning). Replaced with new thermostat and machine stays cool at light loads. When traveling or working a little harder, the Temps go up. If i stop and let it idle, it cools down fairly quickly. I noticed the fan is turning enough for a little air flow, but not enough for high idle. I read in another post about the pwm being stuck open or failed. I've looked through my service manuals and believe i need to start there?? Where is the pwm 9103 located on the machine?
Should be right on the fan motor itself. Been a while. Do you have the hydraulic fan and the belt driven fan?
Ok, I'll look there. Just the hydraulic fan is what I'm seeing.
I have a hydraulic fan. I'll look for the valve and check it and the flow.
Gonna need a serial number. There's a bunch of options for the fan drive. Standard, reversing etc, etc. Need to narrow down where it was built and what option she was equipped with.When I spoke earlier, I was confused with the 330 which had a hydraulic cooler separate from the water and CAC. One being belt driven, the other hydro.
Found pwm9103, it's located directly beneath the fan motor mounted to the outside of frame, caked in 20 lbs of mud. I pulled it apart, cleaned everything and reinstalled. The fan seems to run a little faster with the engine at idle. When i unplug the electrical connector, it goes to high speed. I sure wish I had a theory of operation on the system. I'm wondering if the temp sensor is bad causing erroneous signal to the computer which is keeping the fan from running at the appropriate speed??
Fan speed is dictated by hyd oil temp, intake air temp/pressure and coolant temp. The fact that unplugged gave you full flow says that your PWM valve is working. The problem with coolant is that the computer is not looking at cyl head temperature. It's looking at return coolant temp. If the thermostat is stuck, the return coolant remains cool in the return pipe.
Quick update on my overheating issue, after having a hyd oil cooler fail and getting it fixed, I cleaned out the radiator for better air flow, but that didn't help. I purchased the SLP head kit and replaced the head gasket. Cylinders #4 adn #6 were allowing compression into the coolant, blowing it out and causing the machine to run hot. Its finally fixed now, all hydraulic issues have been addressed. I'm into more cosmetic things and still cleaning the crud out from underneath.Thanks to all that helped.