I have a 2001 S-Crew 4x2 with the 4.6, Towing Package. I am almost always pulling some type of trailer with this truck. From a 1000 lb utility trailer with 4 wheeler up to a 5000 lb boat. I now have 24K miles and have noticed something weird going on with the transmission (I think). It seems to happen at two different times. 1) when the truck is cold and 2) when pulling the boat and it's hot out (90+ degrees). So anyway... Here is what happens. When taking off from a stop it gets really loud and sounds like the engine is revving up. But it's not, at least according to the tachometer. After a few seconds ( I think when it shifts into second) it quiets down and goes away. I can still take off when it does this, but I do seem to loose alot of power.

I would take it into the dealer if it did it during normal operation. But as it is they will likely just tell me I'm crazy because they will never be able to get it to do it for them.

Any ideas?
Thanks
Dan

 

Does your Overdrive Light blink prior or during these episodes?

 

It's not the transmission, it's the engine cooling fan.

The cooling fan is on a heat sensitive clutch. When it is very cold the fluid in the clutch is thick, and spins the fan at high speed. Once it warms up a little the clutch releases and the fan slows down and gets very quiet.

When the radiator is hot the heat activates the clutch and the fan spins fast again, which makes a lot of noise.

Mark

 

Thanks,

I thought it sounded like a fan spinning up, but I had not considered this because the fan is always spinning, and I've never heard of this heat sensitive clutch on the fan.....

Again, Thanks

And no the OD light does not blink, and it didn't matter if it was in OD or not. So the fan must be the culprit of all that noise.

 

Glad you were able to identify the problem.
Just so you'll know, the Overdrive Light will blink to indicate a transmission problem whether you are using the OD or not.

 

As for the power loss when it's hot, it's exactly that. The fan is engaged due to the high temps and the engine being heat soaked. In high temps the performance loss due to the air being less dense are easy to notice.

 

That fan is hard to spin too, eating up power.