Hi,  Can any one other any advise on this.  car has done 135000 miles . fabia vrs 2004.

 

the aux belt was changed at 130000, along with alternator friction pulley and aux tensioner as well as the water pump and drive belt. car has full service history , i have had it 12 years now.

 

any way issue is is i am getting a strange and constant noise that sound like a  fan or wind noise as if the window is open low pitch sound that gets slightly more noticable  at speed above 30mph and can here it at above 70mph and its the same level of noise and sound , coming from the engine bay . .if you take the car out of gear at any speed and let the revs go down its still there and car here it . it is not coming from door seals or windscreen etc . i have got it to do it when the car was not moving.

tonight i took the engine sound cover off the top , kept the bonnet open, switch the lights and blower on full etc trying to have all the switches etc on and listened to any noises that the engine was making and associated moving items . the only part that i could here making a noise was the alternator when all the switches etc where on i could here a fan type motor blowing noise coming from the altenator , when i knocked all the power off and had the car on tick over i could still here the alternator making a noise is this usual?

 

the noise has just started within the last 1500 mile or so . the only way to try and describe it is its sound like almost like a old noisey computer fan type noise you have on a lap topthat needs changing as if the bearing are on the way out and are getting hot   if that makes any sense , i can here the noise inside the car when i am traveling in the car .

 

any ideas any one ?  I think its alternator as may be since changing the front jockey pulley and aux belt and tensioner 6000 miles ago this has in some way now affected the alternator , or its just a life span of alternator etc of the car and it could be any thing, i know its not a clutch , turbo or vacume noise as power is still fine and no smoke etc from the back of the car .

Edited 26 April, 201610 yr by kt600

I would take off the aux. belt and take it for a drive and see if the noise is still there

I had a similar rumble from a classic car - it turned out to the the alternator bearings. I narrowed it down by using a 18" long metal tyre iron, placed on top of the alternator, then rested my temple on it. You can quite easily feel the vibrations. I tried on various parts of the engine and the vibration was barely noticable. On to the alternator and it was like my head was being drilled. Any hard bar (metal or hardwood) will do - long screwdriver possibly, but the handle will damp the vibration

 

I then removed the fan belt and span the alternator by hand and the same noise was there.

 

The good part about this way is that you can be quite precise as to where the noise is from using the bar, when all you can hear from the engine bay is "a noise" from somewhere

 

I should also point out, this should only be done when the car is stationary - definitely don;t take it for a drive while doing this procedure 

 

 

EDIT: My alternator failed after the engine had been rebuilt - the theory was that the alternator was on the end of it's life (almost 50 years but only 60k miles) and the was slightly over tightened when put back on. perhaps with a new tensioner, the belt it tighter than the alternator can now cope with

Edited 26 April, 201610 yr by sdenny

Could be the clutch pully at the end, quite common on them, will be easy to tell when the belts off, new replacements are about 50-60 from a auto parts store.

have had a new clutch pulley on it 6000 miles ago, issue has started last 1500 miles. i know when i put power on , lights etc on and the car is on tick over i can here the alternator making a noise . this shouldnt happen?

 

garage job i think second opinion 

Sounding like the alternator is on the way out :(

the noise has gone now for the time been , think may need a new alternator if it persists , whats the life span of a alternator on these cars any body know ?? car done now 138000 miles...

 

thanks all that have inputted ...

Alternator life - I'd not be too annoyed if an alternator failed electrically at about 60K or mechanically at 90K, but alternators with dried out or otherwise noisy bearings normally run okay but noisily for "some time" longer - how long is a ball of string.

 

On the subject of alternators being noisier when loaded up electrically, yes they will do but a lot of that extra noise will be from the drive belt as it is now under heavy demand and yes that will add loads to the bearings.