`96 audi a6 2.8lr.eng.no heat? the cooling fans were on constantly,as soonas turn on the eng.i disconected the green plug off the a/c compressor.ok. i flushed the cooling system. and the the heater core separtly, i got abit more heat ,i change the thermostat from 87degree c. to 92dr.c.i got abit more heat but not enough for this cold weather. and all the flaps work. the main one, and the other 3,up medle, and bottom? Please what doyou recommend? Thank you.

SOURCE: 2001 Audi A4 2.8 no or little heat

there is a valvve that lets the coolant thru the heater core when heat is selcted then when it is off it goes thru thur the return instead of the heater core i bet your car is running a little off if it is the vavle works of a vacuum line and the vavle has a crack in it

SOURCE: 96 audi a4 heater blows cold air

Are you sure the thermostat is working efficiently? If your getting a little heat when the car is idleing in traffic, but this goes when you start driving again, it suggests the t'stat is stuck open, therefore no temperature can build. When you flushed the system, could you confirm the flow of water through the heater radiator? Was it passing through easily or just a dribble on the point of exit? is there any heat delivered from any of the other heater settings, e.g floor/screen/face vents? If you can get heat from one of these positions it may suggest a heater box issue. There is of course a slim possiblity that the impeller on the engine water pump may have become loose and ineffective. See how you get on. Good luck

SOURCE: engine overheating audi 4.2 a8 1999

I would have the cooling fan checked, and have the thermostat changed. An overheated thermostat (overheating caused by something else) will cause problems in the future.

SOURCE: 2001 Audi S4 Heater doesn't work

Thermostat has failed (stuck open) and needs replacement. It's a big job (5-6 hours charged labor for a shop), and requires the front of the car to be removed. Here's a pic of my car (B5 A4) a few weeks ago when I changed mine:

http://farm3.static.flickr.com/2456/4026320040_32ef32e2d2_m.jpg

There's no way around it either - removing the front of the car is the only way to access it.

SOURCE: Heating doesnt work 2001 Audi 2.8l a4

Sounds like the water level is low. Often the water pipes are higher than the radiator and require bleeding when the car is running, see if there are any bleed screws on the hoses to release the air.