Squealing fan belt

[noogie]

Hi all

My fan belt has started to squeal when I'm going thru the gears.
Its ok when cruising on freeway.
The belt looks ok and appears tight. just wondering whether its an easy fix or needs to go to mechanic.

I drive a td5.

Cheers
Mick

[GuyG]

My air con belt was doing the same, replacing it with a new one stopped the squeal.

[noogie]

I've only got the one belt.
I have 130k on the clock & I haven't changed the belt since I've had it with 61k on the clock.
Maybe she's ready for a new belt, even though the belt looks ok with no visible cracking or deterioration.

What's the opinion.
Is there an adjustment I can do to possibly tighten it more?

[Hoges]

Squeally drive belts are caused by it slipping when there's insuficient friction to cope with "drastic" changes in pulley speed ...like changing gears or starting the engine etc which put enormous stretching stress on the belt as the pulley surface bites for traction. Either the belt has stretched and needs retensioning and/or it has developed a glazed surface...both situations cause a loss of friction. If the belt tensioner is OK then sounds like it's time for a new belt as indicated by GuyG. Replacing said belt should be well within your capabilities...take a look at RAVE. On engines with a tensioner, normally it's simply a matter of levering the tensioner pully with a long spanner and holding it in place while the belt goes slack, simultaneoulsy removing belt. Release tensioner. Then thread new belt over all pulley wheels except tensioner pully, then using said spanner, moving tensioner arm so that you slip belt over it, release arm and pulley is in place....

[bitdist]

Does it do it when you rev a bit just before you would change gears? If so it is probably an exhaust leak rather than a belt. Sounds very similar

[Bess]

As the previous reply said I would also have a good look at the manifold studs. I got caught by what was a definite slipping belt squeal & even had one guy tell me the turbo was on its way out. Finally find a broken stud on the manifold. You have to look hard if all the shields are still on but its worth the effort.
Regards Chris.

[noogie]

It squeals both when changing gears & when just revving it hard. More when driving thru the gears. If I drive slow thru gears, there's no sound.

I will have a look at manifold studs.
Thanks for your help everyone.
I'll report back.
Cheers

[bitdist]

It is usually the studs at each end that go. The first time it happened to me I thought it was a fan belt as well

[noogie]

So is it as easy as removing old studs and replace with new, or does whole manifold come off and must I use a new gasket etc.

I'm tipping it's a fairly involved job??

[Brad110]

Mick

If a stud is broken it is obvious, there will be no nut and end of stud visible.

Problem then is getting the old remaining stud out.' Easy out' with penetrene if possible then cleaning out the old thread and fitting a new one.

Your car isn't that old but have a look around whilst the boys work the go pedal and see what it is. The bearings in the tension ears also squeal when they go.

Good luck. Replace your belt anyway and use this one as a spare.

See ya

[Bess]

If a stud is broken there is a mod to be made to the manifold to prevent it happening again.
Don't quote me but I think the stud holes in the manifold are slightly enlarged & possibly the manifold webbing relieved to allow for expansion & contraction. I had the work done at MR Automotive while getting some other repairs done. Not that expensive.

[noogie]

Mick

If a stud is broken it is obvious, there will be no nut and end of stud visible.

Problem then is getting the old remaining stud out.' Easy out' with penetrene if possible then cleaning out the old thread and fitting a new one.

Your car isn't that old but have a look around whilst the boys work the go pedal and see what it is. The bearings in the tension ears also squeal when they go.

Good luck. Replace your belt anyway and use this one as a spare.

See ya

Cheers Brad

Appreciate it mate:D

[noogie]

Well it looks like its coming from the manifold but the bolts appear to be ok.
I haven't had a close look yet.
Is it possible that they may have just come lose & just require tightening?
Or will manifold have to come off?
Not sure if i should have a go at it myself or not?

[bitdist]

Could be just a leaking gasket or the manifold might not be flat. If there are no broken studs it is an easy thing to do yourself.
Just check that the manifold face is flat before you put it back on and get it machined flat if needed.
I opened out the outer bolt holes in the manifold so that when it expands it will not put sideways pressure on the studs and break them and while mine was off I got it ceramic coated so it does not get as hot anyway.
Others cut out the webbing as well.

[d@rk51d3]

Try torquing them back up. You may even notice some areas where the exhaust is blowing by, showing a black sooty patch, giving you an indication which nuts are loose.

Not a big job to modify the manifold, if you ever have to remove it.

[noogie]

Could be just a leaking gasket or the manifold might not be flat. If there are no broken studs it is an easy thing to do yourself.
Just check that the manifold face is flat before you put it back on and get it machined flat if needed.
I opened out the outer bolt holes in the manifold so that when it expands it will not put sideways pressure on the studs and break them and while mine was off I got it ceramic coated so it does not get as hot anyway.
Others cut out the webbing as well.

Thanks for the tips.
I had a good look & the front bottom manifold stud is broken.
I have it booked in. Gonna have it machined & all studs replaced whilst I have manifold off.
Just wondering is it ok to drive the way it is? Just want to drive to workshop.

Who ceramic coated the surface for you & was that expensive?

Thanks
Mick

[d@rk51d3]

Should be fine to drive.
Just don't go flogging it, take it easy. :)

[noogie]

Muchos gracias everybody.