my 09 a4 is always loosing coolant, engine overheats... i refill and it last for about a week then will empty out again... icheck it everyday but doesnt show signs of leak.....i have a feeling its the head gasket and if it is does anyone know of a link for guidance....checked with a friend from an audi dealer and they quoted 2700...ouch

 

There are test kits that can detect combustion gasses in coolant that would show signs of a head gasket-to-cylinder leak. Most auto parts stores have them. It would be worth your time to try that. Do you have smoke at startup when the engine is cold? It would be a sweet-smelling smoke. Also, check the front of the engine and back of the radiator for white coolant stains. If you have a leak up there under pressure, the fan may be blowing it away rather than allowing it to drip and puddle under the car.