Loud fan in Sawtooth

[MacFox]

Hello all,

So I was using my Sawtooth today and after about an hour or two of use I could hear a noise coming from inside the machine getting louder and louder.  It sounded like an engine revving up.  It happens when the Mac is sitting idle.  This is the second time I have heard this.  I have owned this Mac for over a year and it has only been within the past month that I have heard this revving up noise.

I think it’s coming from one of the fans.  I blew some compressed air on them, but that hasn’t made a difference.

Are one of the fans dying?  Maybe something else entirely?

Thanks in advance 

 

[waynestewart]

Could the thermal paste between the heat sink and the processor need replacing?

 

[MacFox]

Could the thermal paste between the heat sink and the processor need replacing?

I’m not sure what to look for when it comes to whether or thermal paste needs to be replaced, but I know that the heat sink is still firmly attached to the cpu.  There is also a fan attached to the top of the heat sink. Unsure if the cpu came like that or if the previous owner attached the fan to the heat sink for some reason. CPU is an accelerator so maybe that’s why there is both a fan and a heat sink?

 

[mac-cellar]

FWIW - The main case fan in my Quicksilver developed a crack in the plastic of the circular center section of the fan blades.  This allowed it to work itself loose from the glue that holds it to the fan rotor underneath.  The housing of the fan doesn't allow the blades to fly off into the case, but as the blades starting working away from the rotor they made contact with the housing.  This resulted in a loud buzzing noise.  You can find replacement fans on eBay for $15-$20 bucks.