Engine/Transmission (1994 - 1998) Fan Clutch

[Bluhaven]

Went to Lake Mead this past weekend towing my boat, about 8,000 lbs. Water temp. would go up to about 210, 220 on any pull. It was between 115 and 120 air temp but I have towed in that heat before and it never has gotten that hot! I don't think the fan was kicking on because I didn't here it roaring. What temp should the fan kick in? Is there anyway to check the fan to see if it is working right? Don't want to buy parts if it's not needed. I have the original thermastat in.

 

[bmoeller]

Originally posted by Bluhaven

I have the original thermastat in.

Could be part of your problem. I would think that the fan would've turned on if it didn't.

 

[Extreme1]

It's the fan clutch. The only symptom is that it doesn't work when it should. The only test is to replace it. Been there, done that, replaced the thermostat first for no reason.

 

[CumminsPower98]

My fan kicks on hard when my temp gauges get about a couple needle widths below 190º. I would also bet the fan clutch is toast.

 

[Loren]

I posted the following reply at another thread. You can find that thread at



TDR Roundtable > Turbo Diesel Topics, 2nd Generation (1994 - 2002) > 24 Valve Engine and Transmission (1998. 5 - 2002) > Running hot. Did I screw up?



My reply from that thread:



This is my theory, I repeat, THEORY, on how the fan clutch works:



The fan clutch thermostat senses the temperature of the air that is exiting the rear of the radiator. If it senses that the radiator air is too hot, it engages the fan to cool the radiator.



In order for this system to actually cool your engine, as opposed to cooling merely the radiator, you must transfer the engine heat into the radiator. A few things that I can think of can cause this not to happen.

1) A thermostat that is not opening properly to allow coolant to flow into the radiator.

2) A bad water pump.

3) Any other flow restriction.



If the hot water is not getting to the radiator, the radiator will remain cool and the fan clutch will not engage, even though the clutch is operating properly.



An easy item to troubleshoot is the thermostat. You can remove it and heat it in water to see if it opens. If it's not fully open by the appropriate temperature, it's bad. Or you can remove it and run the truck with no thermostat to see if the fan clutch then engages, or if the temperatures are closer to normal climbing a steep hill.



Troubleshooting the water pump is more difficult, but I'm sure there are forum members who can make suggestions on how to do that.



It sounds to me like at least a couple of overheating problems mentioned on this thread are not the result of a bad fan clutch, even though the fan clutch is not engaging when the engine is hot. Check for flow.



Loren

 

[JGK]

When I fixed my KDP and had the fan off, I noticed the little bi-metal coil in the center of the fan hub was "hairy" with dirt and junk. I blasted it off with a shot of compressed air. Since then, I've noticed it works a little better - kicks in at a lower temperature.



FWIW,

-Jay

 

[Bluhaven]

Just got off the phone with Advantage Dodge( Ph:# 800-748-2139) and got the fan clutch for 112. 50 plus shipping, $20. Here in Victorville it was 165. 00. Thanks TDR. Forgot to mention, I told him I got there name the TDR web site and he seemed very surprised and happy of course that they were getting the word out.