have any of you experianced the fan clutch not slipping while the engine is bone cold? mine will blow like a hurricane for a mile or two when i first start off. is this normal? i bought the truck over the summer and never noticed it while it was warm out. strange.

Mine does the same thing, I think it's normal.

It's normal. There are a few threads on this. Annoying, but normal.

Here you go.

http://www.dieselplace.com/forum/showthread.php?t=187998&highlight=loud+fan

And yes it is normal.

I like it:D

That is normal . The fluid in the clutch is thick when cold so it will engage the fan until it warms up.

thanx everybody for the help........guess i shoulda done a search first. but thanx. if it's normal........than let it blow. :eek:

i have a question..... when the engine gets hot does it sound like that? sounds mega dumb i know but i don't think my fan has ever actually come on or locked up at road speed due to coolant temp..?.. i'm probably just not loading the engine enuff? thanks

It will sound like all hell has let loose when it kicks in on a hot engine.Even pulling a heavy trailer in hot weather this doesnt happen often,a sign that these trucks have a very good cooling system.

Try and not run too hard till the fan clutch starts working.

Seems to me that they will do it when cold, mine does each and every day when the temps are low (+5C and colder),....and will kick in when it's very hot and your pulling a good load. Other than that, I never hear it.

stk

All thermo fans do this when cold and first started. They have been doing that since the first fans were used in the 60s.

I don't notice the fan coming on as often on our '06 D/A and '07 D/A as it did on our '02 D/A on hot days pulling a heavy load. I have noticed that on a hot, heavy day it will come on occasionally going through town after a few red lights. Almost embarrassing as i'm accelerating from a stop and the fan just roars for 10-20 seconds or so. What's funny is I Never have seen the temp gauge get above just below 1/2 on any of our 3 trucks no matter how hard we've ran them. Of course they have never been through the mountains either...

. What's funny is I Never have seen the temp gauge get above just below 1/2 on any of our 3 trucks no matter how hard we've ran them.

Those stock instrument clusters keep you in the ball park. The computer sees a different story fortunately.:)

What's funny is I Never have seen the temp gauge get above just below 1/2 on any of our 3 trucks no matter how hard we've ran them. Of course they have never been through the mountains either...
Pull 10K up a long steep grade in 98* weather and not in tow haul mode where the motor is screaming at 3K the whole way up and itll shoot all the way over to the red.:o:

I am pulling 13K with my foot on the floor in the Rockies in temps over 100 and have never come close to overheating the engine. But a very slow pull (below 30) due to sharp curves, not letting the converter lock up, in the same hot weather did come close to overheating the transmission until I added a Mike L cooler and deep pan (and Mobil Delvac ATF) — which has cured things.

i have a question..... when the engine gets hot does it sound like that? sounds mega dumb i know but i don't think my fan has ever actually come on or locked up at road speed due to coolant temp..?.. i'm probably just not loading the engine enuff? thanks

You'll hear it if you're pulling a trailer on a grade in hot weather. Not long, but it'll cycle on and off.

how does the fan "cycle on and off" is it electric controlled as well as the viscous fluid?

It is thermal. the hotter it is, the more the fluid inside the outer portion of the clutch expands, engaging the clutch, making it spin. the fan moves huge amounts of air, dropping the temps, and the spinning forces the fluid (now that it has cooled) back out of the hub, and into the outer portion of the clutch, releasing the clutch. in very cold weather, the fluid tends to stick the 2 parts together, hence the "morning sickness" of a cold truck. if you shut down hot in the summer, the fluid can expand after shutdown, causing morning sickness the next time you start it, no matter the temps.