OK so I was riding on the beach yesterday and the sand was really loose (worse than normal). While I was driving around it started making a loud whoosing type noise. The rpms weren't revving like the trans was slipping and the mph wasn't going up like it was spinning. It almost sounded like a large fan was turned on. Any ideas on what that noise was. I don't think it is anything wrong truck still runs good and shifts fine (at least I hope it's not). I don't know if it matters but my wife had tuned on the a/c. Engine temp never went above where it usually runs.

 

What was the temperature where you were. It might have been your fan clutch engaging if it was hot and you were working the engine through the sand. Is it still doing it?

 

it was about 90-95 outside. no it quit even b/f i left the beach.

 

Yea, I bet it was your fan engaging. Nothing to worry about.

 

Thanks I have been down on the beach alot this summer and this is this first time I noticed it. It's also the fist time I've had the a/c on though.

 

Yea, having the ac on adds a lot of heat.