i was driving down the interstate bot 80-85 mph at bout 100 tep outside and i got off the interstate and i come to a complete stop and when i take off it roars real loud like it does in the morning befor it gets warmed up is my truck ok what is this roar???

Cooling fan, normal.

even in the morning when the motor is not even hot yet and it gets louder as i go then it will quit all of a sudden ?

Again normal, the fan uses a viscous fluid clutch and in the am the fluid is thick, fan locks up and runs a few miles untill fluid thins out.

ok but why did it do it sometime when i took off and some times it did not

and this is the first time it has ever done it durning the day

The fluid is affected by large ambient temp swings. Bottom line is if it comes on and doesn't go off you have a problem or if it doesn't come on ever and your engine trans are running hot you have a problem.

some one told me cuz it is the clutch?

Yes ,it's a viscous fan clutch

so every thing is normal???

Sounds normal to me, it makes me crazy on cold days when I leave the house and I have to listen to it halfway down the street, but that is how they built it, I can live with it:)

The DPers on here call it morning sickness.... http://www.dieselplace.com/forum/showthread.php?t=326787&highlight=morning+sickness

if it is called morning sickness why did it come on durning the day ??

if it is called morning sickness why did it come on durning the day ??
Uh, because it was 100 degrees out?? You probably had a head wind also.

The fan clutch has a thermostat at the very front of the unit, just a few inches from the radiator. Keep in mind that it is sensing temp from ambient (100), trans cooler, intercooler (where you were running a lot of boost through at 85mph on a 100* day) the A/C condenser (which you had on also) and THEN the radiator. So, all of that heat tells the fan clutch when and when not to "lock up" and turn the fan.

Your question has been answered very nicely by several peeps. Any more worrying about it and we will revoke your man card.

ok so every thing is ok right lol??

yes, everything is fine.

As pa32rt said, the fan clutch is engaged/activated by ambient air temperature in the engine compartment. When you are driving along in hot weather, you have lots of air flowing through the grille, which keeps the engine bay somewhat cool. Cool engine bay = no fan.

Then you come right down to a stop and air stops flowing through the grille, so the whole engine bay suddenly gets a big heat soak/shock. The fan clutch reacts to this sudden increase in underhood/stack temperature and then engages right away.......so then when the light turns green and you drive off, you hear the fan because it had 'secretly' engaged just as you came to a stop. Obviously the fan/clutch, even when it is engaged, you still arent going to hear it at idle...because its not turning fast enough to make a roaring sound. Only when you increase the RPM's can you actually tell that the clutch had indeed engaged while you were sitting at the stoplight, heatsoaking the engine bay.

ben

I think the sound is great, sounds like power! Especially in the mornings!