Hi all,

This issue has been with me for a few months now ( as far as I can recall)

Each morning when starting up the car, outside my house... It sounds possibly as if the alternator belt is loose/slack.

I finally decided to check in the engine bay the other morning when it was really quite loud (turning engine off first).

The belt appears to be okay with regards to wear/tightness (but I cant be 100% sure as I don't know how tight it should be)

I also noticed that the bearing/pulley on the end of the alternator is quite brown/rusty.

A day or so later I was at a drive through, so had the window down & the seemed to be a sort of rattle/chattering noise coming from the car.

I pressed the clutch in, as felt maybe it could be the clutch release bearing.

The noise did appear to stop being so bad, but came back again when I took my foot off of the clutch again.

I'm not 100% sure what the problem is...

I think maybe its either the alternator belt, the pulley bearing of the release bearing in the clutch.

Anyone have any ideas please?

I'm quite worried as the car has been like this for quite a few thousand miles now, so my luck may be running out...

Cheers,Pete.

How many miles?

The alternator freewheeling pulley is a big weakness on these cars and they start to fail after about 80k miles. The aux belt drive will then oscillate destructively at engine idle if the pulley has seized.

To test, insert a small screwdriver into the front of the alternator (engine stopped) and engage an internal fan blade. It should be possible to fairly easily turn the fan clockwise as you look at it, but it must grip solidly anticlock. Take great care not to bend the fan blades or damage the stator windings when you do this test.

New pulleys are available from the factors but you need a splined key and a long torx or spline bit (depending on whether alternator is Valeo or Bosch) to change the pulley. If you take the alternator + new pulley to an independent alternator repair shop, they'll fit the new pulley for the price of a beer.

Do a forum search as to removing the alternator. The engine driven cooling fan gets in the way of the bottom bolt, so you can either release the axial fan bolt from behind and slide the whole fan assembly forwards, or chop the head off the offending lower alternator bolt and replace it with a piece of M8 studding, a spring washer and a nut. This makes it dead easy to change the alternator in the future.

rotodiesel.

Edited 13 August, 201015 yr by rotodiesel

Does the V6 TDi have this pulley type too?

I've never checked as I "wrote off" this engine in the procurement phase as being unsuitable for my job.

The INA freewheeling alternator pulley is quite distinctive with a snap on plastic cover which hides the splined fixing nut. It looks completely different from a solid turned pulley. Modified versions (which are not a lot better) have a dab of silver paint on them.

rotodiesel.