squeak/whine from engine bay - what could this be?

[SarahFC]

Hello folks.  There is a whine/squeak coming from my Jazz's engine bay.  It only appears after the engine is warmed up and usually not when I am on accelerator or brakes.  It seems to be intermittent and the car has just had a service:  I am having a small tussle with my service centre about fixing it as it was reported when I put it in for the service.   Would love to know what you think it may be.  The Jazz is 2013.  Any clues or thoughts gratefully received?

There is a small video file of it 'in action'. 

[sparky Paul]

Sounds external to the engine, maybe an alternator bearing or tensioner pulley bearing maybe? I presume the noise changes pitch as you rev the engine?

Shouldn't be too hard to find for a garage with their hands on it.

[culzean]

Agree with SparkyP, probably a aux drive belt tensioner / idler pulley bearing a bit dry, it does spin round at quite a rate even at tickover - maybe something rubbing on the belt.

Is it a CVT or manual box,  don't know if the CVT is capable of making such a noise at standstill,  but the gearbox is on the passenger side of car.   

[SarahFC]

Thanks so much for this:  I need to test what happens when I rev the engine as it normally stops when I put my foot on the accelerator and the brake.  Of course today I cannot get it to make the noise (typical!) so it's a bit of a mystery really.  Am out in it tonight so will see what happens.  It's a CVT. 

We have done the listening screwdriver test on the alternator and it seems sound, so looking at the tensioner/pulley bearing might be the answer.

I wondered if it could be related to the Air conditioning unit, but I have no idea what noise that might make.

Thanks so much for thoughts/expertise so far...

[MartinJG]

Hello folks.  There is a whine/squeak coming from my Jazz's engine bay.  It only appears after the engine is warmed up and usually not when I am on accelerator or brakes.  It seems to be intermittent and the car has just had a service:  I am having a small tussle with my service centre about fixing it as it was reported when I put it in for the service.   Would love to know what you think it may be.  The Jazz is 2013.  Any clues or thoughts gratefully received?

There is a small video file of it 'in action'.

It sounds a bit metallic to me. Bearings?

[sparky Paul]

We have done the listening screwdriver test on the alternator and it seems sound, so looking at the tensioner/pulley bearing might be the answer.

I wondered if it could be related to the Air conditioning unit, but I have no idea what noise that might make.

If it's not alternator, probably idler pulley. Less likely to be aircon pump or water pump.

There is an old trick that sometimes works, find out which it is by using a squirty bottle with water in, aiming it at the centre of each of the the pulleys on the auxiliary belt in turn, until it goes quiet/quieter, or the noise changes.

[culzean]

Can't see any connection between putting brakes on and noise changing / disappearing if it is a bearing on the auxiliary belt though.  There is a steel belt in the CVT gearbox, but if noise is louder on drivers side it is a long way from gearbox.