High pitch whining sound..............

[MADDMOE]

OK so I have been having this high pitch sound for awhile now that only quiets down when i accelerate on my 2009 4.6 but don't drive this car enough to really care til now, finally decided to order a new pulley and once I replaced it the sound was still there, so I replaced the belt Tensioner (comes with a new pulley attached) next and the sound has magically disappeared, also added a new belt...

 

[MADDMOE]

.....well here's an update........turns out the whining noise was my water pump going bad .......now that I changed it along with the thermostat, it's purring like it used to, no more whining sound......

 

[radi0]

Thanks for the tips. My 2011 4.6 also has a supercharger-esque whine. Will need to probe what it is with a screwdriver

 

[MADDMOE]

Thanks for the tips. My 2011 4.6 also has a supercharger-esque whine. Will need to probe what it is with a screwdriver

Chances are if you have high mileage, check your water pump.....

 

[Gunkk]

Idler pulleys are known to make noise as well.