diagnosis help

LeoWyatt

LeoWyatt

LeoWyatt

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Hi all,

We have a Mk4 Polo which recently had a gearbox change and clutch change and it now makes what can best be desribed as a whining noise from around 3000 rpm. I've opened the bonnet and had a look around and from this picture (it's not the one of my car) this is the belt making the noise

belt.jpg


The car did have the cambelt and water pump replaced around january this year. What belt is this?

Cheers
 
That's the alternator belt from what I can see. Think you can get a replacement or tighten it up, should stop the squealing.
 
DaveyD said:
That's the alternator belt from what I can see. Think you can get a replacement or tighten it up, should stop the squealing.
Click to expand...

I'm still learning about cars, what would happen if that split? Will good old haynes tell me how to tighten it? Need to buy one :D

From what I can see there no nicks or splits I just need to tighten, is it hard job?

Thanks for the replies so far :)
 
Looks like the alternator belt. There could be a few reasons why it would be squealing.

Hopefully it's something simple like the belt is worn/strectched or the alternator has just shifted, it'll most likely be held on by a couple of bolts one of which will be attached to an adjectable bracket allowing you to vary the belt tension by moving the alternator away from the engine.

However it's also possible that the alternator is starting to seize which would cause the belt to slip if this is the case you'll be looking at a more expensive fix.
 
LeoWyatt said:
I'm still learning about cars, what would happen if that split?
Click to expand...

The engine wouldn't be charging the battery. You would still be able to drive the car until the battery went flat, but you would need to turn off all uneeded powered devices (radio/heaters/etc).
 
LeoWyatt said:
I'm still learning about cars, what would happen if that split? Will good old haynes tell me how to tighten it? Need to buy one :D

From what I can see there no nicks or splits I just need to tighten, is it hard job?

Thanks for the replies so far :)
Click to expand...

If it split? While driving, not very much would really happen, the car would still be running, for a bit anyway. The alternator is used to keep the battery charged, so when the battery does run out of juice, you'll have no electricity, meaning no sparks to make the petrol go bang.
 
Ok well the battery had a dead cell a few weeks back which I replaced. From what I can see the belt is fine so I'll just have to sort out tightening.
 
LeoWyatt said:
Ok well the battery had a dead cell a few weeks back which I replaced. From what I can see the belt is fine so I'll just have to sort out tightening.
Click to expand...

Carefull not to overtighten it as this will cause the alternator bearings to wear prematurely, if you are unsure get a knowlageable friend to check.
 
That is the alternator belt like everyone else has said, nothing should happen if it does snap however the battery light on your dash may well illuminate to let you know that the battery is not recieving charge. I don't know if on the Polo the alternator belt also drives the water pump if so it could cause your car to overheat if the belt did snap. I had this problem on my old car, alternator belt snapped and caused my top radiator hose to burst.

thedazman
 
thedazman - the water pump was making a racket a few months ago so I got that changed and changed the timing belt at the sametime.

The altenator doesn't seem to run anything, but yes i'll ask a mate to have a look for me.
 
If the car is of an age where the gearbox needed replacing and the alternator belt appears original, for what it's worth I'd just replace it. You may not even be able to tighten it as many cars nowadays have automatic belt tensioners and once they have reached their limit you simply need a new belt.
 
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