New Truck- Noise Under Hood

[ScottK]

I just purchased a 2006 F-350 Super Duty Crew Cab 4X4. Powerstroke 6.0 with auto transmission. I drove the truck around town for 2 weeks and this last weekend I hooked up my 28 foot toy hauler and went to the Oregon Coast. The trip is about 170 miles mostly freeway. The weather was hot in the valley. About 95 according to the truck thermometer. The truck seemed to be running great, but when I came to the first hill on the freeway out of Salem OR there was a roaring noise from under the hood. At the same time there seemed to be a slight decrease in power. This happened several times on the trip to the coast. On the trip home the temperature was even hotter!!!! About 105 on the truck thermometer. The noise would start anytime the truck was pulling hard and over 2000 RPM. There was an obvious loss of power when this happened. Also the truck would not maintain 60 MPH in 5th gear and I noticed over one MPG decrease on the trip home. Could this be a failed fan clutch or be just related to the high temperatures. I ran the truck diagnostic tests on the dashboard computer continually and all readouts were normal. After I got home and unhooked the trailer. I took the truck out for a ride and sure enough the roaring noise was still there after I went up a hill near my home. There also is a high pitch whinning and there just seems to be more noise under the hood. There is no smoke and the truck shows good boost and power otherwise. Are there any ideas to what is wrong???? I am new to this forum and would appreciate any help or advise.
Thanks for the help.......I will be going to the dealer tomorrow.

[New2diesel]

Welcome!!!
The sound that you hear is the electric fan, not a fan clutch. Its normal operation. There is no loss of power, that just your mind playing tricks on you. Mine goes off all the time when towing my 30'er especially going through Arizona where it was 125 degrees. The temp gauge on the dash never moved, so it must be doing its job.

[Heat]

Welcome Scottk !!

The fans on these are mechanical but electronically controlled. When it kicks in, not only do you hear it but it will be robbing you of a few ponies.. No worries though, it does do its job...

Ken.....

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Last edited by Heat : 07-24-2006 at 05:15 AM.

[PowerItUp]

I am posting this for a friend (and yes I'm trying to get him to sing up). He owns a '04 XLT F250 6.0L. He is experiencing a very loud fan noise (or roaring as he calls it) when pulling anything uphill that he says he hasn't heard before. I looked under the hood and seen where it looks like coolant has been puking out and the reservoir was completely empty. He also says he gets a coolant smell in the cab at times when this is happening. I helped him check for codes and there were none. He says it doesn't feel like there is any power loss when it happens but the noise is incredible. It only happens when pulling something uphill. Is this just the electric fan kicking in. He is still under warranty so will be taking it in but wanted to know before.

[mschn99]

the coolant puking is probably due to him trying to pull uphill too fast during this hot weather and getting the motor too toasty, even if the gauge isnt saying so....and the fan roar is just the cooling fan trying to get it all cooled back down......there have been about four threads about the cooling fan roars in the last week....u can tell igs getting hoto outside

[mschn99]

Welcome to the forum, and there is nothing wrong with your truck, as was stated above, you have an electronically controlled, mechanical fan clutch to keep it simple......it "roaring" is just it doing its job to make sure the coolant in the radiator gets cooled down

[PowerItUp]

Thanks for the quick reply Marc. Would the coolant smell in cab be from something wrong and should his reservoir be empty? Or if he was low on coolant, would that be why he maybe hearing the fan more now. He said for the first couple of years pulling and driving it he has never heard it make this noise. I printed out several of the posts about loud fan noise for him to read but he is still concerned.

[mschn99]

Originally Posted by PowerItUp

Thanks for the quick reply Marc. Would the coolant smell in cab be from something wrong and should his reservoir be empty? Or if he was low on coolant, would that be why he maybe hearing the fan more now. He said for the first couple of years pulling and driving it he has never heard it make this noise. I printed out several of the posts about loud fan noise for him to read but he is still concerned.

i dont know bout your guys' temps, but ours have been way abnormally hot.....im guessing this was the scenerio......

Pulling up a hill......was driving fast just like normal......extremely hot day, got the coolant warm and vented some........less coolant in the system, fan has to engage more than normal......tell him to SLOW down when temps are this hot......

Make sure he doesnt put green coolant in to toppit off either...and DONT fill it above the LOW mark that says cold fill.....this will keep purge from happening somewhat....

[PowerItUp]

Thanks Marc. I'm going to take a ride with him while he is pulling somehting just to here it myself. He is also taking it in to the dealer. I think the scenario you mentioned is what is happening. He does say once he levels out from pulling a hill, the noise does stop so that sounds like the fan. I also want to see if it is smoking any when this happens...he said he can't remember or hasn't noticed any smoke. Thanks for the help.

[ScottK]

Thanks, I am glad to hear that the roaring noise was just the truck doing what it is supposed to do. You are probably right about the power, I think I was lifiting my right foot when I heard the fan come on. That seemed like the right thing to do. Nervouse new truck owner!!!! How does the electronic part of the fan lockup work? Under normal cool operation does the fan slip and then lock up only when a certain temperature is reached? I would like to understand this system better. Thanks again