No heat in my heaters!!!!

[audibhoy]

Yesterday i got into my 53 plate A3 2.0 TDI sport and as its freezing put the heaters and to my frustration and annoyance all it did was blow cold air.

Also i have noticed that i need to fill the expansion tank with coolant on a regular???? basis (roughly 3 weeks ish) and the fan seems to be running nearly constant, whether stationary or not!!

would be grateful fo a little/or a lot of help

cheers

 

[andykn]

My old Triumph Dolomite heater went cold when the coolant was low as it was a mini radiator mounted quite high. So when the coolant level went down, this was the first thing to empty.

Meant fill with water without delay.

 

[rickyquicky]

Its almost definately your 'heater matrix' mate.

Andykn is right its like a mini radiator between the dashboard and the bulkhead. This is what makes the air blow hot, and gets hot from your coolant when the engine warms up. If its leaking it wont get warm and you will lose coolant, hence the topping up all the time. Topping it up wont fix it though unfortunately.

Is normally a bitch to do yourself as is normally a dashboard-out job, i've never done an A3 though...hope that helps.

 

[audibhoy]

i totally wont be doing it myself and a 'dashboard out' job sounds to me like a 'labourful' and harsh on the wallet.....any idea on the £££££ for a Audi and non Audi garages?

 

[Geraldy212]

The heater water circuit is separate from the normal radiator cooling circuit. Flow through the internal heating radiator is controlled by a water valve, which opens when you request heat in the car. The main water pump is responsible for providing the pressure to make this happen. Even if the internal radiator was leaking slightly, there should still be coolant flowing through it, and some warm air generated. No heat at all in the car could mean that the control valve is stuck closed, or not receiving the 'open' signal (so check fuses). Yes, it does seem that you have a leak somewhere, but there are many places that this could happen in the total cooling/heating circuits. Suggest you get someone to look closely at the heater water circuit/valve/hoses/clips, before assuming you have a heater radiator leak. This is far cheaper to fix than changing the heater radiator. Note, if the internal heater radiator core is leaking, you should be able to detect this by experiencing higher than normal humidity inside the car. Hope this is not the case. Meanwhile, keep that coolant topped up and at the right concentration of antifreeze. Good luck.

 

[marko157]

Tm having exactly the same problem with my 2001 A4 1.8T,but when I'm driving it blows warm air,when I am stationery its cold.
What could this be?

 

[Geraldy212]

Marko, it sounds rather like your fan blower is not working well. The forward motion of the car is driving some air through the internal heater radiator, which is full of hot coolant. When you stop, no air comes through. However, if the blower is working, then this is a very strange situation, which is harder to explain with the above logic. Perhaps when you stop the air is bypassing the heater matrix, by some strange mechanism. Is the engine running when you are stationary?

 

[Khufu]

I agree that the issue is a low fluid level. I'd be looking for a leak from the radiator or pipes. IIRC the radiators have been known to corrode. As said, if the heater matrix was leaking you'd have a puddle in your car and lots of consendation on the windscreen usually with a greasy film.

Marko, have you checked you coolant level too? Being low will do this if there is an airlock. You will probably find its not so much you moving as the rev's are higher than at idle. Try reving it while sitting still.

 

[audibhoy]

lads,

ws driving it today to the garage and the engine went red hot, so i turned the blower on and reduced the engine temp, i then refilled the coolant ant it was fine again...the mechanic reckons its probably the water pump as there is no puddles in the car. plus by turning the blower on the engine temp went down, which is making me think that the heater matrix/valves/fuses are fine......

mechanic getting back to me tomorrow

any more suggestions/ideas....
cheers

 

[PJLarge]

TDI? Coolant loss?
From experience with an MX-5, a leaking heater matrix will make your windows steam up and possibly / probably damp carpets or mats with a sweet tasting slightly sticky liquid on them. Is this happening?
If not, I'd have a look here:
http://www.audi-sport.net/vb/showthread.php?76277-[2-0-TDI]-How-to-know-if-your-cylinder-head-will-Crack-%28if-it-hasnt-yet%29

Hope it's not, could be an expensive one...

 

[marko157]

the engine is running when stationery,tried revving it,still blowing cold,coolant level is fine.