How would this happen if it is sealed? Should I change the whole radiator as recomended by dealer. It will cost a lot of money. Any suggestions?
Even a sealed cooling system can develop leaks. This can be traced to either lack of maintenance (not changing coolant at least as often as specified by the car’s manufacturer), or to defective parts. How old is this A6?
Should you change the whole radiator? Unless Audi has some revolutionary-design radiators that can be replaced piece by piece, then yes, you need to replace the whole radiator. You could try having the radiator repaired by a specialized radiator shop, but if the leak is the result of corrosion, you will only wind up with another leak in another spot. Probably it is best to just bite the bullet and replace the radiator.
Yes, it will cost a lot of money if you use Audi parts, installed by an Audi dealer. If you go to an independent mechanic, he may be able to save you some money by using aftermarket parts from a non-Audi source.
It’s quite common for radiators to be hit at the front by flying objects, like stones. The grill on your car is there just to obscure to view of the radiator core, and to display the logo. Where is the leak?
Whether the system is closed or open, the radiator can still develop leaks. Even with proper mainteance, radiators don’t last forever. I have owned 11 cars all told,and replaced radiators on 4 of them, usually after 100,000 miles.
Agree Audi parts are expensive but you can get a better deal from an independent garage who uses “after market” parts.