http://www.ebay.co.uk/itm/VOLKSWAGEN-GO ... _599wt_952

What is this? I call it "cold idle control valve" Is that right? I have heard other names, that could just be manufacturers names. As far as I can see it is a common bosch part aswell.

Any info would be sweet!

Yep as the ad says 'auxillary air valve'. It not really an idle valve, more a cold running valve. Idle valves are motorised jobs that can open and close a valve proportionally under closed loop control of the engine management. This one is temperature and time related, so uncontrolled really.

ah! ok so auxiliary air valve is more corrected but they do the same job? anyone know the bosch part number for it on our cars?

That is for K jet cars

Is it that for all K-jet cars? or is it different for different k-jet cars

It has adjustement, it has spring thing that is warmed by electricity and should close when warm, open when cold, but mine does stuck even cleaned what little I could. There was small screw that allowed some sort of adjustment.

It is just a hole that gets blocked when warm, I doubt there are other models, it is rather simple device, but one could get away with any valve that could be operated with choke cable for example, much better, imo. as those K-jet valves tend to get stuck.

I had even holes for attaching that valve in my B200 valve cover, just there was no thread in them, seemed not to be an issue with brute force.

I did use washing machine outlet pipe to connect it to intake manifold, it did work somewhat, I had also rubber pipe, but that did not want to stay in form, so it blocked air flow. However I had to tap that valve every now and then to get idle rpm lower.