Audi A6L2.4 expansion valve has the sound of air leakage.

This car uses a throttle pipe. If there is noise only at the moment when the air conditioning system is turned on, it is normal for the sound to gradually decrease after turning on. & ltbr & gt has been making a lot of noise since it was opened. We should consider whether the throttle pipe is blocked. You can find a 4S shop to clean the throttle pipe or replace it with a new one. & ltbr & gt It should be noted that if the air conditioning duct is in direct contact with the vehicle body, the vibration in the duct will also be transmitted to the vehicle.