Audi TT - Vibrations and noises | HELLA

In the vehicles listed above, operating the air conditioning system may result in vibrations and noises.

These usually occur at about 3500 rpm and reach into the vehicle interior. Overfilling the air conditioning system has been considered as a potential cause.

Another complaint could be the poor performance of the the air conditioning system when exterior temperatures are high. In some cases, this is caused by having too little coolant.

The condenser should receive special attention in both cases. Both the vehicle manufacturer and the independent aftermarket use two different condensers (depth of 16 mm and 20 mm, see drawing). The vehicle manufacturer used a condenser with a depth of 20 mm (1J0820413N) up to chassis No. 8N-5-005-947; from chassis No. 8N-5-005-948 onwards, a condenser with a depth of 16 mm (8N0820411N) was used.

The correct coolant capacities are as follows:

20 mm depth = 750 g / 16 mm depth = 650 g

Note: Some independent aftermarket suppliers only offer one condenser design for all models. The fill volume has to be adjusted if necessary.