299C - S/N JSP00547 I have been chasing an overheating problem on my 299C for way too long. While looking for possible coolant leaks I discovered that the heater core valve was leaking coolant, replaced valve (480-8589: Valve Assembly-Water). I also noticed that the engine temperature would jump 10+/- degrees when I turned on the fan control switch. After looking at the ac/heat blower motor decided to replace it ($80 aftermarket on ebay) as well as the fan control switch ($20 from Cat). I have also replaced the thermostat and engine temperature sensor. All of this was done after the head gasket was replaced. Bottom line, old parts and new parts showed the same results of increased engine temperature 10+/- degrees when fan blower turned on. Temperature decreased by the 10+/- degrees when the fan blower motor was turned off. The only error codes on the display monitor is E361-3 (high engine temp). Any suggestions would be appreciated. Thanks
Have you verified the temp increase with a non contact thermometer?? I am stupidly thinking something electrical causing the gauge, which I assume is electric, to read higher when you turn on the fan blower.
Unfortunately I have not verified with a non contact thermometer since I'm in the cab and working alone. I also agree with your thoughts on the issue being electrical since when the fan in turned on, the temp goes up and when turned off, it goes back down.
OK, checked the temperature of the machine with a non contact thermometer and compared it to the temperature display this morning. The display read 195 degrees, non contact thermometer read 194 with the blower fan in the off position. With the blower fan turned on the display jumped to 217 degrees. Once I turned the blower fan off temp display returned back to 195 degrees. I'm getting a false temperature reading. Any ideas on trouble shooting?
Do you have an electrical schematic.? That would allow you to take a detailed look at the blower fan motor circuit and how it relates to the engine coolant temp sensor circuit.
Is your radiator full, and I do not mean the overflow bottle. Have you put the radiator level, taken the rad cap off and actually checked the fluid level. Have seen this a few times, so just asking. Cannot go by overflow bottles, because if there is a leak in the system, when the radiator cools off and shrinks, it will suck air instead of coolant back into the radiator system. I realize that you did some repairs, but sometimes some air locks can leave a system low. Simple cheap check. Simon C
Nige, Yes, I do have the schematic. Nothing has jumped out to me. I need to get it printed out as blue print.
If the engine temperature actually rises to 217 (not gauge temp) with the cooling fan working, there must be something stopping coolant flow, or the fan is turning too slow. Could a thermostat be staying stuck on. Just wondering? How do the coolant hoses at the radiator feel, or measure with a heat gun. Simon C
Simon C, Thanks for your questions. Yes the machine is parked on a level surface and the radiator is full. Checked with the cap off, coolant is at the top of the fill spout and visible in the sight glass. Here are recent repairs to the machine; New head gasket New radiator cap New engine temperature sensor New thermostat New overflow bottle New sight glass New radiator hoses (all) and clamps New heater core valve New blower motor for heater core / ac evaporator coil New fan blower motor switch
OK, started the machine back up to check coolant hoses. This time when I turned on the fan control switch the temp did not jump like it did previously to 217. It only jumped 5 degrees to 204. The non contact engine temp read 202 at the head next to the thermostat housing. The upper coolant hose read 167 degrees and the lower hose read 126. Was able to grab both hoses with my hand. When I drove the machine when I first reported the 217 degrees, the display continued to climb past 230 causing the overhead alarm. The actual temp was around 204. I believe something is causing a false alarm. The radiator fan may be running a little slow. It doesn't run anywhere near the speed when you disconnect the wiring harness from the fan solenoid.
You have changed a lot of parts. Sounds like you have some kind of control problem on the cooling fan. It should be wide open by 204 is my guess. That rad fan will dictate coolant temperature if rad is all clean. Fact that there is a difference between in and out of rad tells me there is cooling happening. Not sure how much it should be at. Could put tape on fan and check RPM with a hand held tester. Simon C
Was the replacement thermostat that you installed a genuine OEM part or an eBay special.?
That is far too high. The normal difference between inlet and outlet for a radiator in good condition with optimum coolant flow through it should be no more than 20 Fahrenheit degrees
Simon, thanks for the input. The radiator is clean. When you say, there may be some kind of control problem on the cooling fan. There are basically only two things that I could see that may fail, the hydraulic fan motor and the solenoid. The fan runs wide open when the solenoid wiring harness is removed and an alarm code of 1076-5 is generated. Plug the harness back in, the fan slows down and the alarm goes away.
Thermostat is Cat OEM. The only part I purchased off of eBay was the blower motor, $80 compared to $540 from CAT. All other parts are OEM CAT.
Be aware that fan speed is controlled by a signal from the ECM to the fan motor solenoid based on the signals from BOTH the engine coolant temperature and hydraulic oil temperature sensors.
Understood, do you happen to know what engine coolant temperature would activate the signal from the ECM to engage the fan motor solenoid, i.e. wire open?
I'm sorry I don't. I would suspect that a wire open would trigger a Diagnostic Code. However both the coolant temp and hydraulic temp sensors are a fairly simple 2-wire passive type with one side connected to ground. So it must be a variable resistance with temperature. I think the very high difference in radiator inlet/outlet temperature warrants further investigation.
I wondered what was acceptable difference for the two radiator hoses. As I said in post #12, Not sure how much it should be at. Wonder if there could be some blockage in that radiator, and thought as you said Nige, that the trigger wire is either working or not working. I guess he will have to verify the simple stuff first. Simon C
Thanks Nige, the only diagnostic codes are E361-3, high engine temp, and 1076-5 that I generated when I unplugged the wiring harness from the hydraulic fan solenoid. I'm going to be away from the machine for several days. I'll follow back up.
If I can throw anoother curve ball in here. Unless the cooling package (radiator and hydraulic oil cooler) has been removed and completely disassembled then IMHO you can't say it's clean. There is so much packed into such a small space that it is impossible to verify condition without removeal from the machine and complete disassembly. We've been here before........
Thanks Simon, I'll be away from the machine for the next week. I'll do some more checking when I get back. If either you or Nige, or anyone else discover what an acceptable temp difference between the two hoses, please pass it along. Thanks
Think a Photo tach with tape put on the fan might give someone an idea how fast the fan is turning. One thing that I did not see after re-reading this is an Hour Meter reading. Maybe that fan is worn out. Have seen on some other Skid Steers. Will find out when DanTX returns. Simon C
I posted it earlier. 20 Fahrenheit degress maximum (usually it is less than that) with a radiator in perfect condition both inside and out. You had a measured difference of 41. As the Chinaman would say - Sum Ting Wong.
I seen your post above about 20 Fahrenheit, the one I wonder about is what is full RPM of fan when fan motor is good and at what RPM. It either turns the speed it is suppose to with signal wire hooked up and a call for cooling coming from the ECM or it doesn't. If I am wrong Nige, I am all ears. Simon C
Sorry I was driving and didn't see the temp difference. The machine has 3400 hours on it. I'll take the radiator off the machine and bring it to a radiator shop for a through cleaning. The hydraulic fan does not run at full speed unless I unplug the wiring harness to the solenoid.
Who knows, maybe I left a blue shop paper towel in the machine when I did the head gasket. I left one in the turbo drain line......
The fan will only run at high speed once the temperature(s) of the coolant and hydraulic oil are well elevated. An inspection of the solenoid for the fan motor control solenoid, and maybe the fan motor itself, may be called for.
So with harness to the solenoid unplugged, is it still overheating. If so, getting the Radiator cleaned out might be an okay idea, and like Nige said checking the fan motor control solenoid and fan motor itself might be a good idea. Have a nice week off. Simon C
I would have thought that the fan would have been running full bore when the temp was over 217. I don't believe it was. This leads me to believe there may be an issue with the fan motor solenoid since it was not running at high speed with the the high engine temp. It only ran at high speed when I unplugged the wiring harness.
The specified max fan speed with hydraulic oil at normal operating temperature is 2690 ± 50 RPM. You will need a phototach to measure it.
I knew you would have the spec., on the fan speed. That would give a guy a good start. I have a Snap-On phototach from 1988 that works very well. If it is full speed, then radiator clean or repair. If not full speed, then fan motor or solenoid problem would be good to check. Eventually the cause will be evident. Simon C
Simon, Nige, both of you mention to measure the fan speed with a photo tach. I don't have one but I'll either borrow or buy one. I'll measure the RPMs at normal operating engine temp as displayed on the panel of 195 degrees and different intervals up to the overhead alarm of 230 degrees. I'll also measure the speed with the with the solenoid wiring harness off.
Good morning, picked up a photo tach and ran a test. Here are the results. RPM @ Monitor Display Temp 470 @ 71 - right after starting machine 619 @ 100 degrees 820 @ 150 874 @ 175 -- engine at full speed 932 @ 200 1760 @ 206 -- turned on fan switch, temp jumped to 225, continued to climb to overheat alarm -- removed wiring harness from fan solenoid, fan speed peaked @ 3048 rpm -- turned off fan switch, plugged harness back in -- temp dropped to 210 2261 @ 210 1400 @ 204 -- engine to idle 1483 @ 206 -- engine back to full speed Thoughts? Thanks, Dan
Max fan speed appears to be good. Fan speed control control appears to be the problem.
That's what I thought. I did pick up a new fan solenoid, so I''ll change it out and re-run the test.
Fan speed appears to be fixed. It's now runs at 2680 +/- rpm when the temp hits 200'ish degrees and I can hear it engage. There is a but here.... The temp display does still jump 10 to 15 degrees when I turn the fan switch on. Turn the switch off and the temp returns. There are no active error codes, only the stored errors of E361-3, high temp error and 1076-5 error from when the wiring harness was unplugged from the fan solenoid. The temp will also jump 4 or 5 degrees when I move the machine forward. Any ideas?
I would suggest to measure how much amperage the heater fan motor pulls when it is activated. I suppose that there is a possibility of the sensor system performance changing but I don’t recall ever seeing it myself. Also I would be looking at electrical grounding. Can to chassis, engine to chassis, everything basically. Do you have an electrical schematic.? I guess a look at alternator output and belt tension:condition would also not go amiss.
Thanks, I check the fan motor and alternator. Belt is good. Grounding is the common denominator...
Still leaves alternator output open to question. Belt tension OK.? I know on some machines a "low" electrical system voltage can cause all sorts of weird stuff to happen, and I'm not talking about something less than 12v either........ Do you have a schematic.? There are some grounds that it is easy to miss if you don't know where they are.
Hello Nige, Thanks for questions. The alternator is good, output is 14.65 volts with meter, display reads 14. Discovered a terminal block aka fuse holder (267-2744) that looks very questionable while checking voltage on the battery, picture attached. Having a hard time getting a reading. Belt and belt tension are good. Yes, I have a schematic. Will be hunting ground terminals tomorrow.
Those connections do not look good at all. Can affect how machines run cause sometimes you get intermittent power if dirty enough. Once clean I spray with Lloyds Moovit or Fluid Film to keep it from rusting again. If corrosion went up the cable into the cable at all, it will be splice or new cable dependent on where and how easy to fix or replace. Simon C
Thanks Simon. Oh, it's dirty and corroded, I already have a shopping list to replace the fuse assembly, nuts, bolts etc. Will know more tomorrow.
Here is another picture of the fuse holder assembly, 267-2744, next to the battery. I'm guessing that the assembly should have (2) studs with washers and nuts. I'm guessing the only thing holding the wire (101-C45) going to the power fuse module and power relay modules 1 & 2 is corrosion. When I put a meter on the pointy nub, voltages were bouncing around. I'll follow back up in a week since fuse holder will not be in until Thursday.
Wow. Big ball of corrosion. Can cause all kinds of intermittents. Glad you have new coming. Depends on how the lugs on end of cable look you may have to repair. Once new I would spray with some Fluid film or something like it to prevent corrosion. I have all connections on all my equipment and vehicles sprayed to keep them new. They do get coated with dust, but dont get corroded. Which is still a perfect connection. Simon C
Here is my update; replaced the fuse holder, inspected and cleaned all ground contact points as noted in note "A" on the schematic. Replaced some old wire splices (rodents). Tested, cleaned blower motor wiring and fan switch wiring. Applied Fluid Film. Ran machine with a shredder pretty hard for a couple of hours after repairs. When blower motor fan switch, low, medium, high is engaged, the temperature still reflects an increase in temperature of 4+/- degrees on the display panel. The machine ran at a pretty steady 215 degrees. No overheat alarms and no coolant leaks. I'm happy with that. I did receive an error code of 2688-8; Right Drive motor speed sensor 2: abnormal frequency, pulse width, or period, error. It was not persistent, appeared just once. Not happy with that, hopefully just a fluke during my operation test. It was about 85 degrees outside during the test, Texas weather. The machine never had a temp/diagnostic display panel in the past until this overheating issued started. Now I can keep an eye machine and not be running blind. Nige, Simon C, I want to thank you for your help during this fix. Your help is much appreciated. Thank you. DanTX