Acoustical Diagnosis?

[Mesoholics]

We finally got our truck off jack stands after sitting for ... 5 months or so, we heard a sound coming from the motor that I am guessing is the fan clutch or some other belt driven accessory but I am unsure of what it is. I made a crappy video of the sound and I am wondering if someone has heard something similar and can help narrow down the culprit.

The sound did increase as RPM increased but stopped after the truck reached operating temperature.

- We have a new water pump and belt but afaik everything else is original, 95,000 miles / 145,000KM on the truck.

[video=youtube;G4rpJvZBJSw]http://www.youtube.com/watch?v=G4rpJvZBJSw[/video]

 

[Voymom]

We finally got our truck off jack stands after sitting for ... 5 months or so, we heard a sound coming from the motor that I am guessing is the fan clutch or some other belt driven accessory but I am unsure of what it is. I made a crappy video of the sound and I am wondering if someone has heard something similar and can help narrow down the culprit.

The sound did increase as RPM increased but stopped after the truck reached operating temperature.

- We have a new water pump and belt but afaik everything else is original, 95,000 miles / 145,000KM on the truck.

[video=youtube;G4rpJvZBJSw]http://www.youtube.com/watch?v=G4rpJvZBJSw[/video]

A sea lion get wedged in there? On a serious note I have no idea....im interested to know as well.

 

[gmcman]

The only thing that comes to mind at that frequency is the serpentine belt. Sounds like a spot on the belt may be either worn or damaged and at each pass around a certain pulley you are getting a noise. Another option is the fan itself..you can rotate the fan by hand (engine off) and see if it's catching somewhere.

 

[mrphoenix80]

Yep its a belt. The reason it stoped when it warmed up is because the belt shrinks as it warms up, or because the dirt on the belt wore off.

 

[jaguarjoe]

Not many things shrink when they warm up, not many at all.

If the TB is stationary, once the dirt wears off the first time, it should stay off for any starts afterward when still stationary.

Sounds like a wupped out bushing to me.

Harbor Fright has a $5 stethescope for helping find things like this.