Rattle loose sound when aircon is on, belt?

_Dragon_

For the past week i have been hearing a sound like a rattle loose sound, I have now come to the conclusion its something to do with the aircon as it happens when i put the aircon on low which is cold, it doesn't always make the sound but i am sure its to do with the aircon, could it be the belt if it is just happening when i put the aircon on? or would it be more like the pulley bearing?

Sometimes when it happens it will sound load and scary but then the sound goes away.

un1eash

What car is it? Could be the air con, modern cars have a clutch in the pully that allows the air con pump to turn on/off.

_Dragon_

Its  a kia ceed diesel 07. Now I'm thinking its not the aircon as i just been out in the car when i started it up it started to make the sound without putting on the aircon or heating on, it was loud and rattling but only lasted a couple of minutes seemed to stop when i was driving, pulled up in a layby and you could hear it again but not so loud and scary.

I thought if it was the belt it would be screeching or a squeel.

car-man

Could be the Aux belt tensioner or the aux belt has a tiny stone stuck in it.
Could also be the alternator pulley.

gibbo52

Got to be worth getting it checked before it goes bang.

_Dragon_

Yes, the sound is worrying as it could be anything I'm sure its a belt or pulley problem, i will take it into my garage i use as soon as i can, as i dont want a small job turning into a big costly job.

_Dragon_

Took it to the garage at first he thought it was the  airon compressor on its way out as the noise was coming from the front then he said he wasn't sure as the sound seems to come from the back where the alternator is. Got it booked in for monday, i will update after monday.

Its on of those sounds where you cant tell where its coming from.

garryboy

Sounds to me like clutch on alternator pulley.

Heres a link to a YouTube video I made of the failing pulley and also tensioner was shot causing belt to jump about.

_Dragon_

That sounds exactly it, lets hope its not the aircon compressor as i guess that will cost alot. I'm sure the sound is coming from the alternator.

If the sound is alot worse when the aircon is on and its a alternator pulley is it because the alternator is working harder with the aircon on.

garryboy

Yes extra load on the alternator as it now has the added task of working the air conditioning pump.

What engine is it. Mines was VAG 1.9tdi. Was a fairly straightforward job. Just need special tool to remove the pulley off the alternator. Luckily my mate had one.
Was £75 for alternator pulley and new belt tensioner.

If it is aircon pump and you don't want the expense of replacing you can by a short separtine belt that misses out the aircon pulley.