Hi,

I'm new to Audi Forums and saw several postings about heater/heater core issues. I'm having an issue with my 2002 A4 Audi and the dealer so far hasn't been able to figure it out. So far they have flushed the system twice, I had 2 heater cores replaced, 2 thermostats, water pump, and now they want to try the radiator because they said the temp on the right side of the radiator is 185 degrees and on the left side its 85 degrees so they think its now a flow problem in there. The last time they put in the heater core(last week) they said they found some sludge. I got the car back last Friday and the heat worked great all weekend but then the heat suddenly stopped working on Monday(2 days after the heater core was replaced). At times it feels a little warm but then gets back to cold. Also at times at higher rpms some hot air comes out but then gets cold. The temp gauge looks fine, car not overheating, just not getting hot air from the heater. Issue has been going on for about 2 years. I saw several posts here and they were very informative. My question is does the problem I'm having sound like the flushing issue? Also is this something the dealer can handle(can I tell them to keep flushing the system) Thanks.

 

Actually sounds like air in the system..

 

If they have done the flushing they probably didn't do it correctly... Ask them to flush it again and to get rid of the air bubbles...

 

Thanks everyone for your responses!

 

Hi i'm new to this forum too. i also have the same problem.
first had engine overheating problem and no heat coming out from vents.
noticed top rad hose was hot but bottom rad hose was cold.
long story short, replaced thermostat housing, flushed heater core.
checked engine coolant temp sensor resistance with multimeter, seems fine.
resistance goes up as temp goes down and vice versa.
when car is at idle, temp guage stays at mid, but as soon as drive the vehicle, temp quage goes up. after replacing termostat housing, heater core hose gets warm but still no heat from vents.
i'm leaning towards bad water pump. but i don't know how to check it.
does anyone know how to check water pump? i'd appreciate any help.

 

I wanted to post to if anyone lives on the East Coast(PA) and knows any good dealers that they recommend to fix this that would be great. I'm taking it back to the same dealer next week but I'm not to confident they will get it right. Also if someone is near PA that has fixed this before I'd be willing to pay you to fix it right. Thanks.

 

skc: could be the wp, but same answer to you - bleed the air out again. While your bleeding from the upper bleed screw (going into the heater core) rev the engine to around 2500 and see if the water pressure increases or if it still just dribbles..Have to say to do this with a warm engine, not hot

 

thx for the input.
i've tried bleed air in the system. im not sure i'm doing it right.
top up the reservoir and crank the engine n i loosened upper bleed screw couple turns.
as engine gets hot, stream comes out. is this normal? i didn't rev up the engine though.
i guess ill give another shot after christmas. hopefully i won't have to change wp.
i really appreciate for your help.

 

You got it..

Merry Christmas!

 

potential water pump failure