Hey Guys I have the same kind of issues on my 2013 1.6tdi A3, local Bosch garage said it can be a can of worms and straight forward said we need a car for couple of days.
Below are my finings so far.
1.My heating stopped working a few months after my Coolant pump and timing belt was changed (by local Bosch German car specialist garage)
2.Changing the thermostat did not solve the problem (by my self)
3.Looked at all the ventilation flaps and motors, all OK
4.Back flushed the matrix (there was quite a lot of debris, which looked like a pulp from juice but harder). It resolved the problem for a little while. However, after two weeks the heating from the vents was not the same for left and right side of the car (I do not have zone heating), later it went cooler and cooler. If I drove through the city the heating worked however very faintly, if I went on motorway the heating was dead cold after 1 hour of drive.
5.Back flushed the matrix again there oa flow through the matrix (garden hose pressure), flushed all coolant out, removed the thermostat and ran Holts Speedlfush and water through the system.
Now. When I was flushing and running water and cleaner through the system there was fair amount of heat coming through the vents, bear in mind the engine did not go above 50C. I have then put everything back together, replenish with fresh coolant and went for a test drive. Well, the heating was definitely there, faint but equal through the vents, however the engine did not warm up and it stayed 60C. Next day I swapped my new thermostat with the old thermostat, engine is now heating fine however the heating is very very faint.
Through out it all I had no performance problems, MPG stayed the same and the car/engine behaved normal, no OBD codes either. The only thing that did happen was gurgling noises behind the dashboard where the matrix is. The hose coming out of the cabin/matrix is cold while the hose going into the cabin/matrix is hot.
I have called my garage and they said it can be anything, from water pump (which they have changed), to clogged matrix, and they would need the car in for a few days.
What pushes the coolant through the core? Is it only the mechanically water driven pump?
Is the Heather support pump always running? As far as I can see the pump is sucking rather then pumping, since it is on the matrix outlet circuit.
Was the heating working when the water and cleaner was running through, because viscosity was less then coolants? Which would indicate the matrix is blocked or at least partially blocked?
If the check valve was closed constantly, should I not have cold inlet pipes to the matrix?
I know this is a lot of reading, however I would appreciate any thoughts.
A3 8V No Heat Diagnosis
in Audi A3 (8V) Forum
Posted
Did you ever find a solution?