Hi everyone i just wanted to share my joy in finally getting heat in my Audi. Ever since ive owned the car the heater has been cold. Ive changed the thermostat, radiator, hoses, expansion tank, coolant temp sender and sensor and heater controls. Ive also flushed the matrix with water, white vinegar, coke and lemon juice but not much change so i thought il have to do the matrix but it looked a huge task for myself and a garage would charge a fortune. When i bought the car i looked through the service history and there was a receipt for a mahle heater matrix in 2002 so i kind of ruled the matrix out but it appears a heater matrix was bought but never fitted. When i finally got the dash out i realised the heater matrix was a valeo so couldnt of been replaced. I replaced the heater matrix with a new valeo matrix and replaced the foam on all the blend doors in the heater box with aluminium foil tape which is absolutely brilliant and keeps the heat well. The old foam was absolutely shot and completely gone on the blend door nearest to the blower motor. The heater is now really hot and warms up very quickly. It took me 5 days and a lot of chocolate bars to get it done but well worth the hassle. The most difficult part was getting the dash back in and lining up the windscreen heater duct with the heater box. I labelled every screw, bolt, connector and part which helped so much. Id just like to thank everyone on the forum over the years for help and advice. People have said about the matrix and the blend door insulation. I didnt think i would be able to do this job as it was above my capability but after watching lots of videos on youtube and talking to people on the forum i just had to give it a go. I would advise anyone who wants to do this to just take theyre time label everything take photos and just give it a go. Im no mechanic but if anyone wants any advice on how to do this id be happy to share how i done it. When i had the dash out i thought what have i done but dont be overwhemed Thanks.