Hi all

I am in the process of replacing the Serpentine belt and Tensioner pulley in my fiesta

Upon inspection I have noticed what looks like paint peeling, maybe some rust and wear on the alternator idler pulley, I have added a picture of this

I think I could do with replacing this, but have not had any luck finding the replacement pulley anywhere online

I am also not sure how easy this would be to remove without taking the alternator out of the car, if anyone has done this before I would appreciate any advice

Thanks!

 

Edited October 1, 2025Oct 1 by o.hill

It's certainly not broken

I'd certainly not fix it

That does look particularly tatty.  Especially for a 5 year old car in the middle of the country.  Do you know whether it spent the first few years in a coastal area?

18 minutes ago, TomsFocus said:

That does look particularly tatty.  Especially for a 5 year old car in the middle of the country.  Do you know whether it spent the first few years in a coastal area?

It started life in Manchester so potentially near the west coast, I've had the car 18 months or so now

The car does have some rust issues including on the paint work, I suspect that it spent some time in a salvage yard as it is cat s

1 minute ago, o.hill said:

It started life in Manchester so potentially near the west coast, I've had the car 18 months or so now

The car does have some rust issues including on the paint work, I suspect that it spent some time in a salvage yard as it is cat s

Ah, that explains it then.  (Salvage yard...not Manchester being on the coast. )

I would have been concerned about the generator overheating to cause that paint flake otherwise.  But if it sat in a salvage yard, probably with the bonnet up and covered in road salt if it was crashed in winter, then that would make sense.

I don't think it'll be weakened at all, just a bit of surface rust.  So you could just sand it back, then mask and paint it, to look better and prevent any more rust developing.  I don't think Ford will sell the pulley separately, although the MHEV's are too new for the catalogues I can access so can't confirm that.  You would probably have to find the manufacturer and buy a pulley from them, although they may not sell to the public either.  So I would just go with tidying that one up personally.

Just for reference, this is actually a generator because it's on an MHEV.  (Often called BISG by Ford - belt-driven integrated starter generator.)

38 minutes ago, TomsFocus said:

Ah, that explains it then.  (Salvage yard...not Manchester being on the coast. )

I would have been concerned about the generator overheating to cause that paint flake otherwise.  But if it sat in a salvage yard, probably with the bonnet up and covered in road salt if it was crashed in winter, then that would make sense.

I don't think it'll be weakened at all, just a bit of surface rust.  So you could just sand it back, then mask and paint it, to look better and prevent any more rust developing.  I don't think Ford will sell the pulley separately, although the MHEV's are too new for the catalogues I can access so can't confirm that.  You would probably have to find the manufacturer and buy a pulley from them, although they may not sell to the public either.  So I would just go with tidying that one up personally.

Just for reference, this is actually a generator because it's on an MHEV.  (Often called BISG by Ford - belt-driven integrated starter generator.)

Yes I think so, the bonnet and NS fender were replaced and the car was at a salvage auction in November 2021, so likely parts have been exposed.

Interesting thanks, I keep coming across things that are different on the MHEV. I'll try and clean it up for sure, fortunately this wasn't the main issue and it was the tensioner that mainly needed replacing else things may have been trickier