RS6 C6 air conditioning leaks

[mikecl600]

Hello All

First post on the board and im in need of some guidance.

I have a leak somewhere in the air con system on my RS6 and would like any advice on where to start and what are the most common points of failiure.

Only asking as everything is burried and there isnt an easy starting point.

Thanks

[mik15]

have them do a test using a UV contrast substance which should show where the leak is....my guess would be the AC radiator or the evaporator under the dashboard.

What RS6 do you have? i am in Abu Dhabi.

[mikecl600]

a black 2009 with black interior. one of just a few in Dubai.

Do you find it funny to be in a car thats rarer than most supercars.

[mik15]

yeah, but the difference is that while supercars are known by virtually everybody due to their shape/sound, the RS6 is barely noticed by a regular guy, only an enthusiast would recognize it :)

Which shop do you use for repairs? Have you been to Al Nabooda yet to have them check it?

[hahnmgh63]

I'd say what mik15 said about the UV leak detection. You can eyeball around and see if you see an oily residue around the condenser or any of the pipes. When the Freon leaks it also leaks some compressor oil which sometimes leaves a tell tail sign of oil smearing.

[mikecl600]

Al Naboodha have a waiting list that never ends.... I use DAS just the other side of al quoz. They are real helpful but i dont want to be without a car even a day is a pain.

I had a look underneath last night and there is some flouresent dye on the Left of the car just where the exhausts start to converge in the tunnel. Suggests to me the evap is leaking. Next step ill look at the drains on the inside of the car. Once i can confirm the leak i will book it in and get it fixed .

[mik15]

isn't DAS the one specialized in BMW? ran by Ayham? i might be as well confusing them...what color was the trace you saw? i hope it is not coolant because on the left side i don't think it has to do with the AC....

[mikecl600]

Well I found the source of the Leak it was the evaporator. and took me 4 hours to replace it.

Just faor everyones info. You may be able to see the leak if you suspect the evaporator by removing the pollen filters and looing inside the HVAC unit.

Replacement was easier than everyone expected. The dashboard did not need to come out.

The following is how to for an Evaporator replacement

1 Remove the drivers side lower dash cover and centre console side panel and the small duct for the footwell
2 remove the glove box and disconnect all of the MMI cables .(make sure that you dont put ignition on now as you will get an airbag warning later)
3 Remove the side panel to the centre console on the passenger side and the small duct for the footwell
4 when the engine is cold release the pressure in the water system.
5 Clamp the hoses for the RH side heater matrix, do this next to the solenoid valve near the wipers and the return line thats next to the brake reservoir.
6 Disconnect the heater matrix pipe in the RH footwell and let the system drain into a bucket. Approx 2 litres.
7 Dump what ever is left in the AC system by opening one of the gas fill valves.(or ask a garage to suck it out)
8 Remove the pedal box. There is one bolt near the steering colum and 2 bolts that hold on the brake servo. this is accessed from under the bonnet.
9 Remove the 2 bolts that are holding the AC pipes to the evaporator in the drivers side footwell at the upper part of the HVAC.
10 Now heres the odd bit. (from the AUDI manual) Cut the HVAC box open in the passenger footwell to reveal the RH end of the evaporator.
11 Remove the evaporator

Now put everything back together in the reverse order. The only difference is that there is a new cover panl for the HVAC unit where you cut the hole.

Once the glove box is back in you can start the car but make sure the AC is OFF until its regassed and dont forget to bleed the heater matrix after topping the coolant back up.