Toni123

On 1/30/2023 at 10:56 AM, serrobert said:

Update for whoever finds this thread in future.

Apparently my expansion tank is a different revision and has no physical silica bag inside. So no burst silica bag. Also checked with VCDS for errors but aircon unit had no faults.

I ordered an original Valeo heater matrix from Germany for less than 100€, disassembled the entire central tunnel and replaced it.

No leaks around the AC site, but the old heater matrix was almost 100% blocked. After cleaning it I tried to blow inside but only very little air was coming out. Compared to the new it was day and night.

Reassembled everything, refilled the lost coolant, reset all the errors.

Aircon works again, even hotter than before. After another small trip of 1000 km coolant level seems to be stable. Will keep an eye on it in the next weeks.

Hi Thanks for the update, very useful thread.

I have a Audi A3 2016 2.0 TDI and have a similar, I really could do with some advice please.

For the last 6 months or longer, I have had only a warmish air coming thru the heaters, I noticed when driving on the motorway, it does get a bit warmer, but most days it's cold. 

I've also noticed there's coolant coming out of the side vessel of the expansion tank, I believe its spraying out due to the high pressure, also sometimes I can hear a gurgling/ steam noise when in the car. The coolant is very clear and the the engine oil has no cream.

I have recently taken the car to a VW specialist and they believe it's due to a clogged heater matrix, which I plan on changing myself this week.

 Could the clogged heater matrix be causing the high pressure in the expansion tank?

Thanks