Another Dumb Question

[cp2146]

You know, I really hate asking dumb questions on here, but I have one I'm not sure about. Here goes.

Does the 6.4L have a radiator fan clutch? Yesterday my truck started making a noise that sounds like a radiator fan clutch going out (roaring sound like a fan at full speed). Not only that, but it was really pulling a lot of air through the radiator. While parked, if I held it at higher RPM's, the noise would go away after a few seconds...like the clutch is working, but slowly. I've heard the same sound in other vehicles before and it was the fan clutch. The reason I ask is because with all the hoses, tubes, radiator shroud, etc on top of the engine, I actually can't see down in there good enough to tell if it has a fan clutch. I assume it does, just can't see it. Also, is it that during hot weather the fan normally turns faster to help with cooling? I haven't owned a diesel in a while, and not a 6.4L, and not during hot weather, so I have no reference point.

It isn't really a problem, at least not yet, I hope. There's no decrease in performance. It's just a little noisy and I'm not sure if that's normal or not.

[reighnman]

Yes there is a fan clutch, though it's been awhile since I listened for mine but it always cycled on around 200 degrees. Sounds like a helicopter in my engine bay..

[cp2146]

Originally Posted by reighnman

Yes there is a fan clutch, though it's been awhile since I listened for mine but it always cycled on around 200 degrees. Sounds like an helicopter in my engine bay..

Yeah, that description kind of fits. Thanks, I'll keep listening. Anyone else heard theirs do this?

[reighnman]

Plus if you've ever seen the fan you can imagine how much air it pulls

[cp2146]

Originally Posted by reighnman

Plus if you've ever seen the fan you can imagine how much air it pulls

Roger, that.

Worst case, I guess, is that the clutch locks up and the fan is always turning the same RPM's as the engine. I don't think it would really hurt anything, other than sounding like the helicopter, train, jet, insert your description here, until I could get it fixed. If I'm wrong, someone please tell me.

[Spectech]

My truck has done it since I have owned it (3 yrs). I made a post along time ago and also took it into Ford and they said it was normal. It only does it when the truck sits for a hour or two and its real Hot out and I jump in. It makes the fan noise for about a minute and goes away.

[cp2146]

Originally Posted by Spectech

My truck has done it since I have owned it (3 yrs). I made a post along time ago and also took it into Ford and they said it was normal. It only does it when the truck sits for a hour or two and its real Hot out and I jump in. It makes the fan noise for about a minute and goes away.

I've noticed mine only seems to do it (or at least does it worse) right after I've been sitting at a light and idling for a minute or two. Then I'll take off and it will make the god-awful noise (almost a howl) for a few seconds then quit. I made it a point to watch the tach today when it did it and there was no jump in the RPM's, other than normal acceleration, so to me that means the tranny isn't slipping. Also, we've had a few consecutive days in the low 90's, not really what Texans call hot, but definitely the warmest it's been since I bought the truck last October. That being said, I'm going to assume it's just as everyone has been saying...it's the fan, it's temperature related, and it's normal. Again, if I'm wrong, someone please tell me.

[deamsphelps]

I have noticed mine doing that once. I got on here to try and figure out what it was. My coolant was a little low. I added some and have not heard the sound since. I'm not saying that's what did it but it's worth a look.

[cp2146]

Originally Posted by deamsphelps

I have noticed mine doing that once. I got on here to try and figure out what it was. My coolant was a little low. I added some and have not heard the sound since. I'm not saying that's what did it but it's worth a look.

Hmmm, never considered it could be the coolant level. Thanks, man, I'll check it out. The weird part is, it doesn't do it all the time, just every once in a while. In fact, as of this writing, it hasn't done it in a couple of days. I guess the truck is just messing with me again.

[cp2146]

Ha! Well, if all else fails, read the book, right? I was looking at the owner's manual and found this -

Your vehicle is equipped with an engine driven cooling fan drive (also
called a fan clutch). This fan drive changes the fan speed to match the
vehicle’s changing cooling air flow requirements. Fan speed, fan noise
level and fuel consumption all will increase based on the driving
conditions that include trailer towing, hill climbing, heavy loads, high
speed and high ambient temperature, individually or in combination. The
fan drive is designed to provide the minimum fan speed (and resulting
fan noise and fuel consumption) required to meet the ever changing
vehicle cooling air flow requirements. You will hear the amount of fan
noise increasing and decreasing as the engine power requirements and
vehicle driving conditions change as you drive. This is to be expected as
being normal to the operation of your vehicle. High levels of fan noise
might also be heard when your engine is first started, and should
normally decrease after driving for a short time.

I guess that answers my dumb question.