no heat in cabin?

[MGaz]

my AEL A6 never seems to get warm in the cabin. I know it's cold weather at the moment but since owning it in march I think I have only ever seen the water tempature gauge working about 3 times? And each time I managed to get the cabin really nice a hot, but for the rest of the time its as if the needle has been pinned and never moves? And even with the climate control set to 'Hi' and the Aircon switched off all it ever seems to be is slightly warm from the vents.

Do I have a thermostat issue?

I mean it does warm up inside, but its never what i would call 'toasty' like I've easily had from every other car I've owned.

[newsh]

Thermostat stuck open or not there at all.

[urS6Tom]

I've got the same problem. This thread is worth a read

http://www.s2forum.com/forum/showthread.php?t=49409&highlight=Thermostat+s6

[urS6Tom]

and then maybe this?

http://www.wikihow.com/Remove-and-Replace-the-Heater-Core-%28Matrix%29-in-a-%2792-%2798-Audi-C4-%28100/A6/-S4/S6-%29

[Tony Stark]

I'd say try a genuine thermostat. Do the hose pipe flushing trick. Make sure the system is bled of air *including the matrix pipes at the bulkhead.*

The last post on the link says theres no bleed screw for the matrix pipe on the s4. Some have a small hole in the wall of the rubber hose so you can pinch the hose where it fits over the matrix pipe and any air should escape.

[GT500]

I'd say try a genuine thermostat. Do the hose pipe flushing trick. Make sure the system is bled of air *including the matrix pipes at the bulkhead.*

The last post on the link says theres no bleed screw for the matrix pipe on the s4. Some have a small hole in the wall of the rubber hose so you can pinch the hose where it fits over the matrix pipe and any air should escape.

Matrix will be blocked. Don't bother trying to flush. Never works.
New matrix needed. My dads had the same trouble.
Glad my a6 has a toasty heater. Changed my dads. Fair big job..

[byd1380]

Yeah, matrix needed.

[MGaz]

Matrix will be blocked. Don't bother trying to flush. Never works.
New matrix needed. My dads had the same trouble.
Glad my a6 has a toasty heater. Changed my dads. Fair big job..

but if it was the matrix, surly the temperature gauge wouldn't be constantly pinned to the cold position?

And also the 3 times the needle has actually moved from the bottom of the gauge, the cabin got really toasty and warm.

Is it not more likely to be a temperamental thermostat?

[dubmeister]

There is a bleed valve where the pipes go to the matrix under the scuttle cover/ battery area on non a/c cars. sounds like the thermostat in stuck tho. which pipes are hot?

[MGaz]

There is a bleed valve where the pipes go to the matrix under the scuttle cover/ battery area on non a/c cars. sounds like the thermostat in stuck tho. which pipes are hot?

my car has climate control and the battery is under the back seat.

[MGaz]

Question: The Big cooling fan on the rad always seems to be spinning? is this normal?

There is a bleed valve where the pipes go to the matrix under the scuttle cover/ battery area on non a/c cars. sounds like the thermostat in stuck tho. which pipes are hot?

Top engine pipe to rad is hot , bottom pipe from thermostat housing to rad is cold.

heater matrix pipes are warm by the valve on the right of the rear cover.

I'd say try a genuine thermostat. Do the hose pipe flushing trick. Make sure the system is bled of air *including the matrix pipes at the bulkhead.*

The last post on the link says theres no bleed screw for the matrix pipe on the s4. Some have a small hole in the wall of the rubber hose so you can pinch the hose where it fits over the matrix pipe and any air should escape.

New thermostat fitted, still no joy.

Matrix will be blocked. Don't bother trying to flush. Never works.
New matrix needed. My dads had the same trouble.
Glad my a6 has a toasty heater. Changed my dads. Fair big job..

If i remove the valve under the rear cover, i can pour water in to the pipes and presumably it goes thru the matrix.. so i'm guessing its not blocked?

I guess it might be an air lock? Still doesn't explain the non functioning temperature gauge in the car... and the heater working on the 3 times the gauge DID work. .

where's the sensor for the gauge, btw? Also, there is another sensor on the valve under the rear cover. What's this for?

cheers.

[GT500]

Question: The Big cooling fan on the rad always seems to be spinning? is this normal?



Top engine pipe to rad is hot , bottom pipe from thermostat housing to rad is cold.

heater matrix pipes are warm by the valve on the right of the rear cover.



New thermostat fitted, still no joy.



If i remove the valve under the rear cover, i can pour water in to the pipes and presumably it goes thru the matrix.. so i'm guessing its not blocked?

I guess it might be an air lock? Still doesn't explain the non functioning temperature gauge in the car... and the heater working on the 3 times the gauge DID work. .

where's the sensor for the gauge, btw? Also, there is another sensor on the valve under the rear cover. What's this for?

cheers.

Fan spins all the time, yes. Best removed.

Trust me the tiny amount of flow you can get through the matrix is nothing like it needs.

Sensor for gauge is the top one where the top hose goes on to the head.

That sensor on the valve is for the climate control.

Check your temp flap motor is working. its on the right of the heater box but the arm you can see moving is on the left by the wiper motor.

HTH

[5cylinderman]

I understand that you have an an AEL tdi, and I can only assume you have the auto-climate control system with a ***** heater. (me too).
This system relies on small motors to operate flaps etc which are a known beeeatch on the C4.
If I could be so bold to recommend an alternative forum (on this particular crappy heater subject).....
I would advise you to sign up to Audifans.net and search for this topic. I have had unendless problems with my C4 2.5 tdi. Although my vehicle is now "off the road for the mo" you will find a mine of information on answers to your problem. This car is notorious for the servo motors failing within the heater system.
A well remembered member of the Audifans forum aka Bladerunner has posted several cures for your ailments.

[GT500]

I understand that you have an an AEL tdi, and I can only assume you have the auto-climate control system with a ***** heater. (me too).
This system relies on small motors to operate flaps etc which are a known beeeatch on the C4.
If I could be so bold to recommend an alternative forum (on this particular crappy heater subject).....
I would advise you to sign up to Audifans.net and search for this topic. I have had unendless problems with my C4 2.5 tdi. Although my vehicle is now "off the road for the mo" you will find a mine of information on answers to your problem. This car is notorious for the servo motors failing within the heater system.
A well remembered member of the Audifans forum aka Bladerunner has posted several cures for your ailments.

I also go on fans. Perhaps you won't ignore what I said on there...