Blower rattling

[Josh92]

Hi all.

Happy Friday!

I am getting a rattling sound when I turn on the blower on my 2011 Fiesta. The heating and aircon both work it just makes a rattling sound between clicks. I have uploaded a video below.
https://youtube.com/shorts/T9q6f7icpxU?feature=share

Appreciate any advice.

Thanks

 

[Handy Andy]

Freeplay in belt but that is not the chirp. That freeplay is giving the water pump and Alternator a chance to breathe when the belt around the pulleys are not under load.

So you have two things beside the AC that have me concerned - the Water pump if mileage is over 80,000 - this is the sound it makes when the pulley lets the pump relax on its shaft - that squeak.

The other is the Alternator - but it would also make lights flicker from that kind of bearing noise - out of round would make the brushes "bounce" affecting the ability of the stator and rotor to "commutate to the regulator" to charge the system.

This requires the belt to be removed and those pulleys spun to feel for roughness and try to use a runout tool to check for out of round lobbing of a shaft or to place some tension (pull push lift lower) to check for bearing freeplay.

​

The "Groove" on the water pumps' wear point, where the belt lies is a strong clue to this.

 

[Josh92]

Thanks for the detailed reply Andy. I had the Cambelt kit, fan belt and water pump all done in March this year. The car has only done 33k Miles and is an automatic.
So do you think it's most likely the alternator?
Thanks,
Josh

 

[Handy Andy]

The squeak is what has me concerned - alternator draw would make a long-term chirp or squeal - not a squeak, so this sounds to be something of a shaft or shaft to bearing clearance issue - I'm not ruling out nothing yet except electrical load - which it would draw down idle and form that longer tone squeal - not a quick chirp like a shaft turn of bearing roll.

 

[scotman]

It’s bearings, either the A/C compressor, alternator or water pump.
This is where a mechanics stethoscope is nice to have!