Whining sound from left side of engine on cold starts

[M]

Hi all

I have owned an 06 MK5 GTI for about 4 months now and over the past week or so I have noticed a noise on cold starts. The best way I can describe it is like a high pitched "wah wah wah" that's in time with the engine; not too loud. It comes from the driver's side of the engine block and goes away after a couple of minutes. The engine also has to be stone cold; if I drive the car, shut it off for 2-3 hours and start the engine again, it won't be there.

Just curious if anyone can suggest possible suspects? I know these cars have a reputation for the timing belt and tensioner playing up. Also open to the possibility of it just being a cold start quirk of these cars that I have never noticed before, in which case I'm an idiot

I'll try to get a video up soon if needs be.

Thanks

[blingsta]

could it be the balance shaft cog/sprocket?

[pudding]

A video clip will help. 

A lot of German engines use straight cut teeth on the oil pump gears which can be noisy from cold, but other than that I can't thing of anything that would make a noise from cold.

[M]

Sorry for the delay. I took this video on a cold start just as the idle started to drop. You can just about hear the noise especially around the 8 to 12 seconds mark.

[GVK]

 Take off aux belt and try it, if its still there look at timing belt tensioner/idler and water pump..

[pudding]

Has the engine had a recent cambelt change?

Sounds exactly like mine, and I did a belt change a few months ago - all genuine parts. 

It was previously silent on the old timing belt parts.  You can't over or under tension the belt as the tensioner is idiot proof, so it's probably just the rubber belt making a noise as VW are constantly changing suppliers, so the rubber compound might be slightly different.

I wouldn't worry about it mate, it's a normal sound.