Squeals like a pig

[Salisburytree]

What action would you take next?

My mk6 belt squeals like a pig.

It's a new belt. I noticed some slack on the tensioner so I stuck a new one on, possibly made it slightly quieter but still making a noise. All the pulleys seems good when the belt is off. Belt is clean. Spray wd40 on the belt it seems to stop for a little bit...how does that make sence?

[DanMK7uk]

What brand belt have you fitted? Is the back of the belt shiny and smooth like Bosch, or textured Like a conti belt by Continental ? A little 80 grit across the shiny part can grip it up abit, there are also belt dressers out there never used any myself.

Generally speaking, if the belt goes quite when sprayed it will be the belt.

Is everything alined ?


If your mk6 is fitted with an OAP on alternator check that is ok but probably your belt, iv had new belts play about and make you chase around for something else.

Its either slipping or mis alined.

Cheers.

[Salisburytree]

What brand belt have you fitted? Is the back of the belt shiny and smooth like Bosch, or textured Like a conti belt by Continental ? A little 80 grit across the shiny part can grip it up abit, there are also belt dressers out there never used any myself.

Generally speaking, if the belt goes quite when sprayed it will be the belt.

Is everything alined ?


If your mk6 is fitted with an OAP on alternator check that is ok but probably your belt, iv had new belts play about and make you chase around for something else.

Its either slipping or mis alined.

Cheers.

Thanks for the reply!

Everything looks aligned, belt sat in the middle of each pulley. Will double check the alternator is bolted on properly.

I will check the brand in the morning but I'm sure it's pretty smooth on the backside, if so I will rough it up and see what that does.... thanks for the tip.

Can I ask what OAP stands for ?

[DanMK7uk]

Overrunning alternator pulley

Every time the engine speed reduces - for example during a gear change etc - the alternators inertia creates resistance against the belt. OAPs allow the alternator to “free-wheel” or “overrun” when the belt suddenly slows down . This prevents the belt from slipping and reduces vibration, wear and chirp noises.

Plenty of videos out there easy to check.

Thats if your van has one mate im not absolutely sure you do suspect it will have.

Yeah the 80 grit works well particularly if the issue is when damp / wet gives bit more grip on the pulleys.

I do like the conti belts, as they have a rough finish on the flat part of the belt.
Cheers

[Salisburytree]

viewtopic.php?f=5&t=209689
My alternator looks just the same as this one with the clutch pulley. Would that be what you are referring too?

I feel like the more revs I give the less it squeals, but that would make sence with belt slipping?

[DanMK7uk]

Yes clutch pulley/ OAP

[andz327]

Overrunning alternator pulley

Every time the engine speed reduces - for example during a gear change etc - the alternators inertia creates resistance against the belt. OAPs allow the alternator to “free-wheel” or “overrun” when the belt suddenly slows down . This prevents the belt from slipping and reduces vibration, wear and chirp noises.

Plenty of videos out there easy to check.

Thats if your van has one mate im not absolutely sure you do suspect it will have.

Yeah the 80 grit works well particularly if the issue is when damp / wet gives bit more grip on the pulleys.

I do like the conti belts, as they have a rough finish on the flat part of the belt.
Cheers

Yes clutch pulley/ OAP

Old age pensioner wtf Dan

Sent from my SM-G990B using Tapatalk

[DanMK7uk]

How are your getting on Mr Salisbury

[Salisburytree]

Okay so the sand paper made a difference but still slipping abit. Its was certainly smooth on the back face so iv got a conti belt on order. If that does the trick I will advise on my findings and recommend no one bye any other belt!

[DanMK7uk]

Cool, what make belt is currently on the van out of interest? By chance Bosch ?
What happens is in my experience, the smooth belts glaze over so slightly, this obviously increases slip or the possibilities.

Can also just give the smooth idler pulleys a light sand, but don’t remove material.

Cheers

[Salisburytree]

Yes its a bosch belt on there. Are these known for being sh*t?
It looks nice and new, most probably put on by the previous owner (iv only had the truck a month if that)

[DanMK7uk]

Aha, something like that, Known to slip in My experience. I dont fit them no more straight to conti belt. Cheers

[DanMK7uk]

As I Say, they glaze over. Rough up can get them quiet. Anyway hopefully your new belt sorts it. Keep us posted.

[Salisburytree]

I will be sure to update !

[Salisburytree]

Conti belt fitted this eve. Only ran the truck for a few minutes but not squeal. Will update tomorrow eve after a day of driving.

I'm lost with the logic of this belt... it feels smoother than the one I just took off!