noisy fan

[FX4OffRoad1992]

ive been told by a few people that it is common for a coolant fan to be very loud when you first start your truck/car and when it "warms up" your fan should quiet down.
This is true in my truck, or somewhat so, as the fan is loud when i first start it, but quiets down before the temperature gauge even moves at all. it does this in all weather, so the cold couldn't be doing it.
I find that revving the engine to about 2-2.5k rpm's and holding it there for about 20-30 seconds makes it quiet down, or if i start it and take off, at about 30-40 mph it will quiet down.
My fan also is loud when i crank my truck and its still warm. i could literally have it running for hours, cut it off and crank it right back up and this noise would occur.
the real weird thing is that it didn't do this for the first YEAR that i owned it! it just started out of no where one day, and has been doing it for about 3 months now.
any help would be greatly appreciated!

 

[Big Jim M]

The fan clutch is fluid operated. When the fan stops moving the fluid drains back into the area that APPLIES the clutch principles. So when restarted the fan DOES turn. This insures a HOT ENGINE will immediatly have cooling. As the fan turns in cold air the fluid is allowed by a valve to go back into the area that OPENS the clutch. At that time the fan isn't controlled by the engine and slows down.
I've not seen a new vehicle that didn't do zackly what your USED vehicle is doing now. Perhaps you have become sensitive to the sound?
Big JIm

 

[FX4OffRoad1992]

yeah maybe i just never noticed it... it just is extremely loud, almost like some kind of jet airplane or something like a voooooooooooossshhhhhhhh, i have dual exhaust that is fairly loud, and you can't even hear my exhaust over the fan when my truck is first started, but i always used to remember being able to hear my exhaust over everything else before when the truck was first started up, and anytime it was running actually...

 

[feellnfroggy]

By 40 the fan usually cuts off anyways, hot or cold. Simply because 40 mph is the necessary speed to air cool the motor without the fan. Every car Ive ever drove the fan cut off at 40 and if i was overheating then the engine started to cool down at 40, with some exception, obviously.

 

[FX4OffRoad1992]

i know, but its just odd that one day i start my truck and hear nothing but exhaust, the next day i start it and the fan noise makes it sound like im turning airplane propellers preparing for lift off.. i didn't do anything to the exhaust.... waiiiittttt. could cutting the tips off of my exhaust have made it just that tad bit quieter to be able to hear my noisy fan when i start my truck? because now that i think about it, i started noticing the excessive fan noise about the same time that i cut the tips off of my exhaust.... could it be that the fan noise was there the whole time and that im just now noticing it because i removed my exhaust tips?! could removing the tips make my exhaust that much quieter?

 

[feellnfroggy]

Its possible if you cut the tips from outside the rear bumper in length to just under the rear bumper or bed. This would kinda muffle the sound from your ears in the cab, tho not necessarily anyone else.

 

[FX4OffRoad1992]

thats it then... thanks man! never had a clue that removing the tips would make it so much quieter in the cab, but it makes sense now!

 

[bobbywalter]

exaust under truck- loud-

exaust exit truck- quiet.


clutch is going on fan. need fresh clutch or its just been colder then normal lately and its just hangin up a bit.

 

[FX4OffRoad1992]

when it first started, it did it all the time, and i had the fan clutch replaced and it just did it when first starting the truck... figured it was better than all the time, but i'd really like it to not do it at all.

 

[bobbywalter]

when it first started, it did it all the time, and i had the fan clutch replaced and it just did it when first starting the truck... figured it was better than all the time, but i'd really like it to not do it at all.

then you would need an electric fan.

the fan is doing what it is supposed to at cold startup. i would just let it be....maybe turn up the radio if it is buggin ya too much

 

[feellnfroggy]

clutch under tha cab I can see that, but If it was under the bed right at the rear end, the sound I can see the sound waves traveling out from under the truck like normal and being baffled by all the material between the rear of the bed and the cab. But just outside the bed, there is nothing really to baffle the sound from the cab. I have no muffler on my truck and it exits right next to the fuel tank but on the passenger sde, i only have cats and its NOT that loud. A flowmaster would be louder.