6.0 Fan Noise When Towing Up Hill

[Raptor 88]

I have an 04 Ford F350 dually and pull a long toy hauler. When going up a hill, the fan clutch kicks in and I get this high pitch squeal when the fan is engaged. Anyone else experience this? Anyone have a resolution? Appreciate you help...it really is irratating!

[HAM_RADIO_MAN]

How old is your fan belt? Could also be a bad fan clutch. The fan clutch on these are electro-viscus meaning the PCM decides when to run the fan. They all have bearings and other moving parts that can fail. First I would check your belt and idler pullies.
WELCOME TO THE .ORG !!

[dazdillenger]

I'd think if the belt was slipping you would notice it more when you turned sharp or used the ac-the power steering/ac compressor put much more load on the engine than the fan clutch. Likely the actual clutch is going out.

[Raptor 88]

Thanks for the responses. My fan belt actually broke recently going over a mountain pass so it does have a new belt. The old belt was making a noise when the clutch pulled in and that stopped (belt was slipping). Now, it's like a high pitch squeal..sounds like a bearing going bad. Have you guys seen the clutches go out on these? It only happens when I'm pullng my trailer up a steep hill. Are they hard to replace? Thanks!

[Heckler]

Mine does the exact same thing, and I have never found out what it is, I have been told it could be the pulleys on the fan, ficm, etc but I dont know. It really doesnt sound like a belt slipping, it's more like a high pitched radio frequency, it's very high pitched and it comes on slowly and goes away slowly, only when pulling a trailer, up a grade, when the fan kicks in.

[Acidsniper]

It sounds like it's either a belt tensioner / idler pully or the fan clutch. A good way to test this is to put as much load on the engine as possible without the fan on (i.e. A/C on, uphill, etc, etc before the fan kicks in), do you hear the sound? If so then it's more than likely a tensioner / pully that's gone bad. If not then do the same with the fan on, is the sound there now? If so, then it's probably the fan clutch which can wear over time.

The reason you hear it so much more when pulling it mainly just from the stress / strain on the motor and the higher RPMs required when pulling especially up grade.

Fan clutches can and do wear over time in all vehicles, it's not a "problem" per se with the 6.0s. You'll typically see it more on heavier duty trucks that are used as haulers due to the increased strain put on the engines regularly.

[Heckler]

Mine will only do it when the fan kicks in and when towing, uphill, it does not come on when the fan comes on towing on flat ground?? only under those specific conditions. My truck only has 39k miles on it and it has done this even when it only had 20k on it.

[Raptor 88]

Great comments guys. Update on my truck...I had a mechanic (that I trust) look at my fan/clutch and they ran all the tests and said it's fine. I will try the the test recommend with the AC going up a hill and see if I can get the fan to engage without pulling my trailer...I'm starting to think it's the tensioner/pully that has a bearing going bad....thanks again for the discussion.

[madracer77]

i have a 05 450 4door work truck, got it with 37k on it. the truck is always on the heavy side at around 16k lbs and ive had fan problems from the get go, had the fan cluth, serp belt and pulleys replaced a bunch of times under warranty and squeels like a pig about 7500 miles after being replaced and fan clutch keeps bouncing back and forth from high speed to low speed and not at all , up hill down hill at any rpm at speeds over 45mph, and still does it after motor was replaced at 130k!!!! damn i miss my old work truck!!!!! this damn thing spends more time with the hood up then on the road

[Raptor 88]

I went to a reputable auto repair place near my home and they tested the clutch fan...all checked out good. He recommended to do nothing. I may look at replacing the belt tensioner (mentioned earlier in this thread as a possibility). I'm starting to think this is just something that I can't fix. I also have had major issues with this truck...mainly engine related. I would like to get a new 450 but don't have $70K laying around.