I am going to try this on my 97 A4....

VWVortex.com - Heater core - broken-off male nipple/fitting repair DIY

Do you think I could use Copper instead of Aluminum. Since I am not going to get it done by a machine shop (too expensive) I am considering different ideas and materials. My concern is that copper would react with the other metals in the car, The head and block - I think they call it galvanic corrosion, but I just do not know anything about this.

 

Yes, the Copper has the chance to react with the other metals in the car, as well as have a negative reaction to the coolant used in the vehicle. Stick with whats in the car from the factory to be safe.

 

Thanks for the information.. I will use Aluminum - as from what I understand (unless wrong. please correct if wrong) the radiator is aluminum.