Whining Noise When Accelerating & Coasting In Gear?

[BenMurphy43]

Hello!

Recently I have been hearing a whining noise when accelerating (especially in 1st and 2nd)

I have a 2.0TDCI Mk4 Mondeo but the car is pulling fine (actually "drag raced" my cousin in his 2.0TDCI Mk4) and there's no loss of power both cars were more or less parallel.

The whining noise also happens when the vehicle is coasting (no throttle whatsoever) while in gear even between 1-2 thousand revs which indicates it isn't a turbo whine so I'm guessing serpentine belt as it's coming from the engine bay? No noise at idle but it kicks back in when revving, even if I hold it at around 1,200rpm

If anybody else's has done this before I'd love to hear from you as I have searched far and wide for a diagnosis! Even quite a few mechanic's have said they aren't 100% sure!?

Any help is greatly appreciated

[jmurray01]

Sounds like a worn out gearbox to me, plain and simple. Our old MK4 Fiesta had that in 1st gear.

Although having said that, it sounds like it is doing it when free-revving the engine? If so, perhaps the above is not the case.

[Stoney871]

Sounds like a bearing in the gearbox.

[BenMurphy43]

Appreciate the feedback fellas.

Apologies if my first post wasn't too clear, it also whines in neutral when revving so it definitely isn't a gearbox issue, all gear selections are smooth too.

[chemfusion]

Sounds like what I've got, which was tracked down to noisy bearings in the alternator

[BenMurphy43]

Possibility because on the odd occasion the battery light shows for a few seconds? Only happened a few times though