Starting "chirp" / belt?

[TimW]

Hi all,

Long-time lurker and new owner of a MK5 GTI '07.

I have a question regarding a noise when starting the car, it only occurs on turnover and I can only describe it as a slight 'squeak/chirp'? It doesn't continue when the car is running and no other issues with the car when running.

It sounds almost belt-related but the car is on 101k miles and it had a belt and tensioner pulley kit with a new water pump and alternator drive belt replaced at 90k by a reputable VAG specialist (just over 12 months ago)

Any help would be much appreciated.

Thanks,
Tim

[DBXdarkangel]

Starter motor not disengaging maybe?

[TimW]

It’s right at the beginning of the turnover, as opposed to lingering at the end as if it was the starter not disengaging.

Sometimes it’s a little laboured in its start if that makes sense?

[mjmallia]

Have you checked the alternator pulley as they do seize.....easy to test with the engine off and tensioner slacked off, as it should only spin freely one way when the alternator shaft is kept stationary.

If it seizes it can make the belt skip on the pulley, which in turn makes the chirp noise.

[TimW]

If it helps, I have filmed it and uploaded a short clip here

[pudding]

Did you slacken off the belt and check the alternator pulley as suggested?  Whilst you're there, spin the belt tensioner pulley by hand and see if it makes a whirring noise.  If it does, it's shot and needs replacing.

[TimW]

How would I slack off the pulley?

[pudding]

https://www.pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/10-ENGINE-Replacing_Belt_Tensioner/10-ENGINE-Replacing_Belt_Tensioner.htm