Hello all im looking at replacing the heater core as it only blows cold air or very luke warm, can anyone give me some tips is it best to take it from the drivers side ive tried looking everywere for a how to do it with pictures but cant find one 

 

thanks 

            Andy

Hello Andy,

I take it you have already established that the heater core is partially blocked, or are you assuming it is since it will only blow a small amount of heat? 

If you have proved the core is partially blocked then fine to replace it. If not, it would be well worth checking whether the heater controls are working properly first.

Kind regards,

Gareth. 

Hello Andrew.

It's unusual nowadays for a heater core to block without also having similar problems throughout the whole cooling system, so like Gareth I question whether your core is truly blocked. Have you tried connecting a garden hose to the heater to test if there is any restriction to flow? (I don't know off hand quite where you break into the system to do so, but that is the only real proof I know of for a blockage.)

Have you eliminated other cause of poor cabin cooling such as faulty controls, damaged air ducts, etc. all of which are going to be easier and cheaper to resolve than a heater matrix? Do you have other symptoms of defects in the cooling system as a whole?

Thank you guys im just going to have a look this morning ive had loads of issues with this horrible BKD engine as in the porus head  and the poor idle of the BKD will let ya know the out come 

Hello all looking at the 2 silver pipes I notice the left hand side one gets boiling so you cant touch it but the right hand side one only gets just warm is this correct ? or is this a blocked matrix also ive taken the heater flap motor off and just to check it can anyone tell me how to check this with a multi meter please …  

Just now, mortzz said:

On the first picture I re plugged it back in but no matter what I do with the heater controls the arm does not move , on the second picture the same thing the flap does not move , on the last picture the white cylinder moves does move up and down and I play with  the heater controls im thinking multiple failure's 

Andrew.

If the hot and merely warm silver pipes are the heater inlet and outlet then something is definitely stopping the flow of water. Whether that is a blocked matrix or a seized water valve has not been established conclusively, but my money would be on the controls being faulty. Unfortunately I have no idea how to test it.

Thanks Cliff , with the bad weather today I could not get  under the bonnet to take off both matrix pipes and get a hose to see if there is any blockage , but I think there is issues as well with the flaps..

quick update on this guys ,, just to confirm that its not to bad a job getting the matrix out on a 2003 a3tdi s line 8p and also it comes out of the passenger side footwell not the drivers side, mine came out fairly easy once you pull the silver pipes off I personally would not use any tool around the silver pipes just get hold of them and pull them its a pain but doable ,, so I looked at just about all the electric flaps and tried them all manually and still no heat so just taken the matrix out , it seems to be full of little black bits so ive cleaned it as much as I could with boiling water then gone and bought  oven pride not the foam the stuff ,  you leave on for around 2 to 4 hours so will let ya know when it goes back in but I also think my radiator is not working as it should

Glad you're getting somewhere. I hope there's no aluminium in the matrix if you are using the caustic version of oven cleaner. (The less effective oven cleaners are just surfactants; the effective stuff contains caustic soda as well.)

im a tad fed up and unsure were to go with this as ive cleaned the matrix and a fair amount of little black bits came out and water flows through ok,  so after putting back on no change cold air,,, so im confused as the matrix pipes are hot in and out and it blows air out so why no hot... ive taken most of the motors off from the flaps to manually move flaps and still nothing … just don't get it... the only thing left is the Heater Control Valve as  in this.. 

https://www.ebay.co.uk/itm/FOR-Audi-A3-Seat-Alhambra-Skoda-Octavia-Superb-Heater-Coolant-Control-Valve/332860804571?fits=Car+Make%3AAudi|Model%3AA3&epid=7025363221&hash=item4d800ccddb:g:CWIAAOSwQwRb2xRg

 

 

but my theory is surly if the heater control valve is not working the matrix pipes would not be hot but they are ? it must stop the the heat before the matrix ? no idea any help please

 

some good info here 

http://www.audi-portal.com/en/diagnostic/actuators_18918.html

Andrew.

I have no practical experience of the heating system so I can't advise further I'm afraid, though I do note that the link 

http://www.audi-portal.com/en/diagnostic/actuators_18918.html

mentions the need to bleed air out of the auxiliary heater, whatever that is.

Very much the same issues. Had a water pump and thermostat changed so these are not an issue. Will be changing interior temperature sensor, heater core matrix /heater control unit in that order.