Hi all,
I too had the relay 30 issue and eventually got round to buying a new one and getting the very kind gentleman at Continental Car Services here in Auckland to fit it for me.

$35 for the relay and no charge for fitting. I must say I was very impressed with the professional manner and service I got from everyone at Continental Cars – I can’t sing their praises enough and if I ever buy a new Audi that’s where I’ll be buying it from.

Anyway the car ran perfectly from the moment the new relay was fitted and there has been no occurrence of that annoying rough performance since.

I have since done a little research as I was interested to see what ‘Relay 30’ did and how it could affect the performance so much. Looking at a wiring diagram I obtained, it’s listed as ‘Relief Relay for X Contact’ (J59 on page 45/8) and according to Google, its function is to shut off all un-necessary electrics whilst the starter motor is cranking the engine. You know the sort of thing, when you start the engine the radio momentarily turns off. Looking at my old relay, the dry joints, and yes there where 2 lovely dry joints, where in the main solenoid circuit and the main switching circuit. So I guess the thing would have been chattering and sending a massive amount of noise around what should be DC circuits. I couldn’t quite see if the ECU was driven from this circuit but if it was it would be like powering the device from AC current rather than DC.

Perhaps someone has a list of all the circuits that this relay controls.

Well done forum – keep up the good work….
Johnhh
PS. Anyone know anything about rumbling noises from gearboxes?