Clutch fan, normal or not?
 

Seems anytime I am not keeping my speed up i.e. 0-25mph stop and go traffic for more than 5 minutes or cruising around on the dirt roads with some slight incline the clutch fan kicks on and is loud. Louder than any other truck Ive driven or heard. Had a passenger with me yesterday and as soon as it kicked on he looked at me and said "what the hell is that"

The noise is just the sound of the fan, no whining, growling, clicking or anything other than ordinary. But it is loud. As if the fan is in the cab, really. To me, it is excessive. And why is it coming on so much with just low speed driving? Normal or should I look into seeing if it needs replaced. Temps are down into the 40-50 so it is not hot out. Doesnt matter where my heat selection is, it does it whether it is on or off.

Hunting season coming up. If I have to listen to that 80,000cfm jet engine fan kicking on all the time, no way in hell am I going to sneak up on anything.

Not normal.

Replace it - or better yet, go with an RF269 and a DCC FK-75 controller combo.

Thank you Ser. Figured.. but I'm new to this gen truck and wanted to make sure it wasn't normal, never know anymore

Looks like for the price of a new one I should just go with the E fan and controller kit.

Oye - hold on a sec - it's a 2007, right? If so, it uses a PCM-controlled fan clutch, NOT a bimetallic internal t'stat like on the 2006 and older trucks.

In that case, I don't think changin' it is gonna help - the fan clutch cooling strategy is programmed into the PCM and is likely not faulty. Possibly a reflash to a newer PCM strategy may help, but that's just a SWAG. Ask yer dealer to check if updates are available?

Sorry - fergot to check yer truck's vintage. My bad. Yall need to update yer profile ( upper right ).

MGD

Oops. I'll get that fixed up real quick.
07 it is.

I'll have to dig around to bring up some info on what yer sayin.. pcm controlled eh.
Sounds like serious business


So to figure out why it is coming on so often at low speeds. And why it is so loud. There is no fluctuation of the temp (dash gauge) before or during the fan kicking on that I can see.

Nice work! I read the same thread - Windsor's post is key. If the clutch STAYS engaged - (and you sure WILL know if it is, lol) the fan clutch is probably toast. Otherwise, it likely just the nature of the cooling strategy in yer specific PCM.

For now - I'd keep an eye on it - note any significant changes.

Best of luck

MGD

Mine is an '06. It [the fan] always sounds like an 18 wheeler engine for a minute or so on the first start on cold mornings.

Normal.

Hey guys.

Bringing this back real quick as the problem seems to be getting worse with the weather warming up and it needs to be fixed. I'll probably drop it off sometime next week to have it looked at but figured Id get some ideas on what could be going on before I go in there.

07 5.4L

Still same issue, fan coming on after 25 minutes of normal driving, normal temps. But there are more symptoms that come with the fan coming on. The more serious one is I am getting very hard, loud banging downshifts when the fan is engaged. Sometimes to the point I will pull over and sit for 15 minutes just so the fan will go off and I can go about getting home. During this time btw, the temp gauge is normal as always and no other signs of a heat issue. The downshifts ONLY happen when I can hear the fan is engaged. Otherwise the trans feels normal during normal driving. Once the clutch fan comes on, it stays on until one of two things, It sits long enough to cool down or I can get at a good cruising speed on the highway long enough but even then most the time it will stay on.

What is the relationship with the trans and clutch fan? Trans fluid looks and smells normal but I am thinking of taking it in for a drain and fill just to eliminate the possibility of it being an issue. Does the trans fluid use the radiator as a cooler or is that separate? I know they shared a radiator in my last truck but havent even had a chance to look on this one.

Sorry, still have not had time to make it to the dealer to check for any updates......working 7 days a week this time of the year.



I have gone to bigger tires, 285/70/17 with no calibration... if that would have anything to do with it.


Thanks

Trans cooler is separate.

Positives:

- Less parasitic drag on the engine.
- Ability to cool while idling in traffic.
- Better access to engine pulley area.
- Better sound; no "fan whir" from the engine bay.

Negatives:

- Reduced cooling potential. There's simply no way an electric fan can flow the same CFM as an engine driven one.
- Greater alternator load.
- More arguable: Less reliable. In my experience, the typical failure mode of an engine-driven fan is a seized pulley, which means the fan will be driven at max capacity. An electric fan's usual failure mode is a bad relay or temp sensor, which means the fan won't turn on at all. If something's going to go wrong, I'd rather have too much cooling than not enough.

For me the cons outweigh the pros. For a truck, that is; for something like a sports car it'd be a different story. Something to think about????

PCM reads trans temperature as well as coolant temp. All of that is PCM strategy to the cooling fan

AC demands will also drive the fan into a different strategy. Defrost uses AC as well. Try turning AC off and repeat your drive and see what happens

Your gauges are nothing more than dummy lights with needles. you need to read actual temperatures via the OBDII port before you can dismiss an actual overheating incident is occuring. The temperature gauge won't move from the middle until the coolant temp is at the point of engine damage or limp mode. I use a scangauge II. Monitors coolant and trans temps all the time.

I agree. I also use the scangauge II. Highway cruise in summer months should be around 190° to mid 180s around town.

I brought my scangauge down to Florida with me to drive my dads mustang back. At idle it goes up to about 220° and is in the normal range on the highway, so I know his fan isn't working right.

Just saying, 220° doesn't move the needle in the cluster at all, but my scangauge shows me what's really going on.

Bottom line, get one or something similar and see the actual head temps and coolant temps.

What about a thermostat? If you aren't seeing a high temp on your needle but your fan is engaging maybe the thermostat is stuck? Or sticking?