The Deere guy did diagnostics on my 2016 310 L, and discovered that although the computer was telling the fan clutch to disengage to let the engine warm up, it was failing to disengage. Deere wants $710 just for the part. The tech says that I can change it myself. Is there any way to repair these things or am I stuck getting sodomized to the tune of $700? Is there an aftermarket part?
Is it air activated? I've had a few that get stuck from sitting. A good rap with a hammer when it's disengage mode usually did the trick.
On the face of it, this doesn't make sense. The minimum ECT (engine coolant temperature) is controlled by the thermostat. A fan clutch is usually only there to reduce fuel consumption and noise when the fan is not needed.
There is a thermostat, which the Deere guy suggested I replace before winter as they tend to have issues, but he also said the fan was an issue too. Your analysis makes sense however. If the thermostat is closed, then no icy water can enter the engine. But the malfunctioning fan might have some effect when the engine heats up, the thermostat opens, and lets coolant into the engine. I think it's electric, as there is a wiring pigtail plugged into it. You can see the issue on the diagnostics screen, as the computer is saying that the fan should be running at 0 RPMs because the engine is cold, but it's actually running at engine RPMs. I will try whacking it with a hammer to see if I can free it up. Would it make sense to put a VOM on it to see if the coil that energizes the clutch is not burned out? Check the electrical connection for corrosion? Wondering if power supplied to the clutch engages or disengages the fan, and if I could check voltage at the connector?
We need the DEERE GOD here. He will want the machine serial number. As soon as he is threw playing footsie with the wife, he will mosey in here.
Yes, the voltmeter makes sense. You'll see soon enough how it activates, or if it doesn't get voltage from the harness, and proceed from there. There's a lot bigger things to worry about than the fan not turning off. They do that to save fuel and noise. Neither matters much to a homeowner or small business. As long as it doesn't fail the other way and overheat, don't mess with it much. Get a non contact thermometer to monitor the true engine temp and radiator temp as it warms up, then change the thermostat if it acts up. No need to make problems where they don't exist. I'm curious if the tech CHECKED the valves? I don't know what is in the way on that engine, but it's usually simple to remove the valve cover and check the valves, then you know they're fine, or not.
He told me not to spend the money taking all the exhaust stuff off to check anything at 1600 hours. So no valves. The Scangauge will show temps, so I can get a curve plotted for normal operation.
It is an electrically controlled viscous fan. They tend to run fast regardless of signal from the computer when cold due to the liquid within the fan being cold. As it warms up it should slow down to commanded speed. If not then there is an issue. Do me a favor. Start the engine cold. Let it idle for 5 minutes. Then go to full throttle and leave it there. You will hear the fan roar. After about 5 - 10 minutes at full rpm does the fan quiet down (slow down)? More times than not we see wiring issues with the fan. Are there any codes?
Edit: While I could not find any theory on it in the manuals the fans do run at full speed when cold. We have seen many times especially when we are running flow tests and we are waiting for the hydraulics and the engine to warm up. The fan is at full speed until a predetermined temperature is reached. I confirmed that running both an SK and an SL. The SK starts to slow the fan at 130*F, and the SL starts to slow the fan at 120*F. My theory on this now is it is designed into the software most likely to add parasitic load to the cold engine to help it warm up faster. Again run your machine at full throttle while watching engine temp. It should slow the fan at approximately 120*F.
Would the fan running full time be the default mode and the power turn it off? Bob
It takes a PWM signal to the fan to slow the fan down. Lack of a PWM signal (ie: an open circuit) and the fan will run full speed. So yes the default is full speed to protect the engine. The fan will run full speed if (1) a temperature sensor (I believe there are 6 sensors depending on emission level) is reporting an overheat condition, (2) an electrical issue with the fan drive circuit or (3) an electrical circuit issue with any of the above mentioned sensors.
Thank you, I don't have a clue how these work but if the fan was getting the power signal to slow down and won't slow down that would point to a bad fan hub? Bob
That would be correct. If there were no electrical issues and the fan did not respond to the command then it would be a defective fan drive.
Thanks for the education. Bob
Here is some more. This is what they use on the backhoe.
The diagnostic screen shows that the computer is trying to make the fan run at 0 RPMS, but it's running at full speed.
See post #8 and 9. What happens after engine reaches 130*F from cold start up? 150*F? Are there any codes, active or stored?
I wonder if I can buy one direct instead of through Deere?
No codes as far as I can see. And due to the leak, I've not let it heat up enough to check. I'll let you know.
For $700 I'd be at the local NAPA trying to match it up with something. Somehow we got along without crap like that before "they" decided we needed crap like that. Joe H
Deere part prices are worse than mafia loan sharks.