i have about 5500 miles on my truck. This weekend i got in it after it had set all night and it was about 90F outside. I cranked it up and heard the fan come on. As i gave her gas the fan got really loud. Whats this about? First time i've had it do it and hasn't done it since.

 

Prior to this have you ever heard the clutch fan engage? I wonder if it was just that but if you havent experienced it before it would take you off guard. If you are familiar and used to the clutch fan engaging then I have no idea.

 

no don't know anything about that. I purchased the truck in Dec and been pretty cold during the winter so maybe its never engaged. The thing sounded like a airplane though and the more pedal i gave it the louder it roared. i left my driveway going up hill about 20mph slowly then it quit about 30 seconds later. Havn't heard it since????

 

My job 1 does that as well on hot days (roughly 85+ degrees) after it has been sitting in the sun. My guess is that it is the initial shock of the heat to the engine since it has not been running. I either let the truck idle for about 30 seconds or drive very slow for about 30 seconds and it always goes away soon after that. I'm sure some tech will chime in as to if it is an issue to just drive away and ignore it.

 

clutch fan it was. Typical sound for a diesel to make.

 

Im with you, the first time I heard it I thought something just happened. Apparently that fan can push some serious air.

 

If you really wanted to hear something...I drove 10 ton tactical trucks in the Army, had 400hp detroits right behind the drivers seat. When those fans would kick in, you about had some dirty pants.

 

 

i'm wondering if there is a temp sensor up front and with the open grill structure on these trucks it causes a premature activation for cooling since the sun is hitting it directly. Is this possible? Has to be related to heat somehow. The funny thing is that the truck hadn't been driven in over 24hours. It may also be the water in the radiator is heated so high that once the water is pushed out and flowing the sensor reads high heat and activates the fan. Now that sounds more logical.

 

Mine does the same thing...it always goes away within a minute or so.

 

guess its ok then but was surprised when the fan came on for a second when the truck was cold. Never experienced that before.