1997 a6 heater not working

Newbie Joined: Feb 01, 2011 Posts: 12

hi all.just registerd here...
hi to all for a great site.
just bought myself an a6 1997 1.8...estate....156000 miles.
the main problem i have is the heating is not working.
fan works ok on all speeds but no warm air.
ive flushed through the coolant and replaced with clean water....
the two pipes running to the heater matrix are hot but still no warm air inside...
i was wondering if its related to another problem..
the temp guage doessnt work so maybe the problem is related...
ive bought a new temp sender unit but i cant find where to replace it...theres so many sensors under the bonnet i have no idea where to find it.tried to buy a manual for the a6 but cant find one
any help would be greatfully recieved.......

Posted: Tue Feb 01, 2011 10:29 pm

Hello there,

1) Does your car have air con with digital climate controls?

If it does, read the following link and check that the V68 motor is working on the heater unit. The motor is on the passenger side under a plastic cover. You can also see the white plastic arms moving on the drivers side when you adjust the temperature.

http://www.audifans.net/ftopic-23831-days0-orderasc-30.html

2) Have you tried bleeding the heater matrix?

3) Your heater matrix may well be full of rust. I had this problem on mine, and although I could flush some water through it I couldn't get any heat from it at all. Replacing the matrix solved the problem. Though I would convince yourself it is blocked before changing it!

Hope this helps. Rob

Posted: Tue Feb 01, 2011 11:32 pm

Hi, I helped someone else on here a couple of weeks ago with an identical issue.

What you should do is to undo the hoses leading to the matrix at the engine side, then flush water through the matrix with a hose pipe so you can build up some pressure and a good flow through, if it's just full of crap this should sort it, if water isn't able to pass through then there may be an issue with one of the heater valves (some teeth o'n a cog were broken on the other fellas) or the matrix is blocked, either way it'll tell you if it can pass water at a decent rate so you know where to look

Newbie Joined: Feb 01, 2011 Posts: 12

thanks for the help....
its non aircon/climate control..
flushed the matrix thru last night and its made a slight improvement but only blows slightly warm air.....
im suspecting the matrix will need replacing...
at first just a small amount of rusty water came out of the matrix but after a while cleared and a better flow of water came out...not as fast as water going in but better....
my a6 takes a long time to warm up anyway...on tick over a good 25 mins
before the radiator fans kick in so maybe i need to try a longer run before the heating gets hotter....
is it a hard job to replace the matrix...i see a lot can be done from the engine compartment but does a lot of the dash also have to come out...
how much will a new matrix cost me...
thanks for the help so far....

Posted: Thu Feb 03, 2011 8:47 am

If it takes that long for your car to warm up I would definitely take a look at your thermostat, it sounds like it may be jammed open. Never changed a heater matrix on an a6 before but it probably will require the dash to come out.

I would expect to pay somewhere around £50-100 for a new one.

Posted: Thu Feb 03, 2011 1:52 pm

Not certain on the non ac model, but you probably have to take the centre console out.

I suggest you have a look in the Haynes manual as it explains the whole procedure.

http://www.haynes.co.uk/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&productId=12811

A new genuine heater matrix is about £80.

Rob

Posted: Thu Feb 03, 2011 3:18 pm

I had the same problem as you for a couple of years until i finally accepted that it was the heater matrix that was blocked up with rust.... I got a new matrix from Euro car prats for £30, though not quite the same dimensions as the one i took out it fits and works well and i now have a lovley and toasty heater. The Haynes manual is a valuble reference for this job, it's not small but very doable, it involves removing the centre console and switch gear (carefully!), battery, wiper linkage, and screen surrounds to get the heater unit out, then once out you can change over the matrix quite easily, make sure you have some silicon sealer available too.......

at least you dont have a corrado.... I had to take the whole dashboard out to do the same job! now that was a nightmare!

Newbie Joined: Feb 01, 2011 Posts: 12

thanks for the advice so far...
fitted a new thermostat and engine heats up quicker..
flushed the matrix thru again and heating started working better....
at first was getting hot inside so i was happy...after a couple of days
heating not working as well again.....
could it be the water pump not working properly.....or maybe matrix getting blocked up again.....im doing the cambelt soon so think ill also replace the water pump while im there....
had a look under the bonnet and luckily the matrix can be removed from
the engine compartment so that will be the next job.....
new matrix from eurocarparts is only £21...