Technical Drive belt and Alternator pulley

[Adam1984]

Hello.

So I have come to conclude that I need a new drive belt and an alternator pulley. My symptoms are somewhat similar below:

A faulty overrunning alternator pulley can cause unusual noises, vibrations, and potentially lead to belt issues, battery charging problems, and even overheating, requiring replacement.
Here's a more detailed look at the symptoms:
1. Unusual Noises:

Squealing, Whining, or Whistling: A faulty pulley can cause high-pitched noises from the engine compartment.

Buzzing or Chirping: A short buzzing sound (1-5 seconds) during engine start-up or shut-down can indicate a worn bearing in the pulley.
Rattling or Ticking: A loud rattling or ticking noise from the engine at idle can be an early symptom.
Grinding or Squealing: A failing pulley can cause a grinding or squealing sound to come from your engine.
Vibrations: A worn pulley can cause vibrations in the belt drive system.

2. Belt Issues:

Belt Slippage: A faulty pulley can cause the belt to slip, leading to a burning rubber smell.

Excessive Belt Wear: A bad pulley can cause the belt to wear out prematurely.
Belt Misalignment: A faulty pulley can cause the belt to run off-track.

3. Charging Problems:

Battery Not Charging:
If the pulley is bad, it can lock up or spin free in both ways, preventing the alternator from charging the battery.

Dim or Flickering Headlights:
A faulty alternator pulley can lead to electrical issues, such as dim or flickering headlights.

4. Other Symptoms:

Engine Overheating:
A faulty pulley can disrupt the smooth movement of the belt, causing it to heat up and potentially lead to overheating.

Engine Accessories Stop Working:
If the alternator pulley fails, it can cause the engine accessories (like power steering or AC compressor) to stop working.
Burning Rubber Smell:
A faulty pulley can cause the belt to slip, leading to a burning rubber smell.
Visible Wear:
Look for scoring marks or damage on the pulley itself.
Pulley Feels Loose:
If the pulley feels very loose when you try to turn it, it could be a sign of a problem.

So my question is, I need a 4 Rib belt as I don't have air con on my vehicle.

But I can't seem to find a 4 rib alternator pulley. Do these exist or do I have to buy the alternator as a whole?

Thanks.

 

[Herts Hillhopper]

I’m pretty sure you don’t have an over-run pulley or clutch in your alternator — the stop/start cars do, with an ‘intelligent alternator’. But that is controlled by the battery condition sensor fitted with stop/start. You don’t have stop start so are unlikely to have an intelligent alternator.

- Did you check the belt tension?
- Did you try running the car with the alternator belt removed? (Only briefly- not a good idea to run very long like that)
- Has your alternator got very wet? (The bearings can fail if flooded)
- With the belt removed, can you turn the alternator easily? Any sign of bearing damage?

If all the above are ok, then maybe a new pulley, but that’s the part that’s least likely to fail.

 

[Adam1984]

I’m pretty sure you don’t have an over-run pulley or clutch in your alternator — the stop/start cars do, with an ‘intelligent alternator’. But that is controlled by the battery condition sensor fitted with stop/start. You don’t have stop start so are unlikely to have an intelligent alternator.

Did you check the belt tension?
Did you try running the car with the alternator belt removed? (Only briefly- not a good idea to run very long like that)
Has your alternator got very wet? (The bearings can fail if flooded)

If all the above are ok, then maybe a new pulley, but that’s the part that’s least likely to fail.

So what pulley do I need then?

What's this highlighted part?

 

[Herts Hillhopper]

So what pulley do I need then?

What's this highlighted part?

As I said, do you need a pulley?

 

[Panda IIs]

I’m pretty sure you don’t have an over-run pulley or clutch in your alternator — the stop/start cars do, with an ‘intelligent alternator’. But that is controlled by the battery condition sensor fitted with stop/start. You don’t have stop start so are unlikely to have an intelligent alternator.

- Did you check the belt tension?
- Did you try running the car with the alternator belt removed? (Only briefly- not a good idea to run very long like that)
- Has your alternator got very wet? (The bearings can fail if flooded)
- With the belt removed, can you turn the alternator easily? Any sign of bearing damage?

If all the above are ok, then maybe a new pulley, but that’s the part that’s least likely to fail.

The original post has more than a whiff of AI about it... All I am saying is that that is a generic answer that knows no different between alternator type fitted, it is simply an assimilation of all things "failing alternator" on the interweb...

You can't beat a step by step fault finding exercise.

 

[Herts Hillhopper]

So what pulley do I need then?

What's this highlighted part?

Your photo shows a 'plain' pulley -- ie there is no clutch on it. If it did have it would look like this (below) and probably have a black plastic cap on the 'open' end - shown here underneath. (Ignore the dimensions shown - this is just an example). Note how it is the same diameter all along, whereas yours has an obviously smaller section nearer the alternator itself.

 

[Adam1984]

Your photo shows a 'plain' pulley -- ie there is no clutch on it. If it did have it would look like this (below) and probably have a black plastic cap on the 'open' end - shown here underneath. (Ignore the dimensions shown - this is just an example). Note how it is the same diameter all along, whereas yours has an obviously smaller section nearer the alternator itself.

View attachment 464508

So what is the part that I circled above then in red? If it's not a pulley or a clutch, what is it? A tensioner?

 

[Herts Hillhopper]

So what is the part that I circled above then in red? If it's not a pulley or a clutch, what is it? A tensioner?

It is a pulley, but contains no clutch. It is also very unlikely to have worn as there are no moving parts in it, and the belt (rubber) is much softer than the pulley (steel), so the belt will wear first.

Go back to the questions asked above...

• did you check the belt tension? (How far round can you twist it). It will have been removed to do teh timing belt so may not be back correctly?
• If you remove the belt, can you turn the alternator easily by hand without feeling any 'binding' or grinding (showing a failing alternator bearing)?
• Has the alternator ever been flooded (or washed with a pressure washer)? grit from floodwater will eat an alternator quite quickly

Also, I very much doubt that (1) you can remove that pulley from the alternator, and (2) that if you could, you could find a replacement for it

 

[Adam1984]

Basically I seen a mechanic try and turn it. He said it was stopping when he turned it back one way. So told me the freewheel clutch needed replacing. Is he talking ********?

So I might just try and get a new belt then

 

[Adam1984]

Basically I seen a mechanic try and turn it. He said it was stopping when he turned it back one way. So told me the freewheel clutch needed replacing. Is he talking ********?

So I might just try and get a new belt then

If I get a new belt as they are cheap.

Which brand would you recommend for the drive belt, Gates, Dayco, INA or another?

 

[Herts Hillhopper]

If I get a new belt as they are cheap.

Which brand would you recommend for the drive belt, Gates, Dayco, INA or another?

Whatever you can get... not many choices.
Will you be fitting it yourself? If not, let the mechanic buy it... then if its not right it's their problem to fix it

 

[Adam1984]

Whatever you can get... not many choices.
Will you be fitting it yourself? If not, let the mechanic buy it... then if its not right it's their problem to fix it

Haha.

I will be buying it myself, and a mechanic will fit it for me. The belt will be less than £10, I know which belt I need.

I hear that Gates belts have a good coating on them to make them better, or what other brand you recommend?

 

[AnthonyH]

Can you take some video of the alternator in operation and upload it here?

My alternator pulley is very noisy, today i was listening to it deafening out a hole i have in my exhaust, its that noisy. But i tested the alternator and its 100% good. So i'm not going to do anything with the alternator or belts...just fix the exhaust leak.

 

[Adam1984]

Can you take some video of the alternator in operation and upload it here?

My alternator pulley is very noisy, today i was listening to it deafening out a hole i have in my exhaust, its that noisy. But i tested the alternator and its 100% good. So i'm not going to do anything with the alternator or belts...just fix the exhaust leak.

The noise doesn't sound too bad on the videos, but much worse off camera.

 

[AnthonyH]

The video format isn't supported on this website.

 

[Adam1984]

The video format isn't supported on this website.

Any way I can change the video format?

 

[AnthonyH]

OK, seems to be working on chrome but not firefox that i usually use.

 

[AnthonyH]

The belt isn't slipping or it'd squeal, when an alternator fails it will have a high pitched whine, so I reckon your alternator is good.

I can hear the sound you're investigating, it may well be the pulley, but i question whether you need to do anything here really, i mean my alternator pulley is a lot louder and i'm not concerned.

 

[Adam1984]

OK, seems to be working on chrome but not firefox that i usually use.

No worries.

So what brand belt would you recommend? My cambelt and water pump I had done the other week was INA brand.

 

[Adam1984]

The belt isn't slipping, when an alternator fails it will have a high pitched whine, so I reckon your alternator is good.

I can hear the sound you're investigating, it may well be the pulley, but i question whether you need to do anything here really, i mean my alternator is a lot louder and i'm not concerned.

I did an alternator test with a reader and it came back with good on the reading.

Where is the pulley? I can't seem to find the part anywhere online either. Just a 6 rib pulley, but I need a 4.