Flushed my coolant system last night due to lack of heat. All murky brown water. I couldn’t find the red valve or get the lower radiator hose off, so I removed the sensor on the bottom line. Does this sensor go bad? Could it cause no heat? I filled it with water, ran the car and drained it again then let the hose run on it for a while until it was clear again. I decided to run the universal dex cool(I know, only run pink). I thought the cooling system holds 8 litres, I was only able to get 4 litres of antifreeze and maybe a pint of water in there afer running with the cap off. Do I have a lot of air in my cooling system or what? My heat situation didn’t really improve much. It gets a little heat out now. My driveway is slanted up a little maybe I should run it on flat ground with the coolant cap off? Any other way to get air out of it? Is my heat supposed to on/off/high/low?

 

It could be air but if it didnt work before then im not sure thats it. Sounds like your heater core could be plugged up. I think you could take the lines off of it in the engine bay and try to run water through it.

 

explains how to get to the drain plug, good read if you haven't read it yet:

http://audizine.com/forum/showthread.php?t=73219

 

Yes, but it should throw its own code if it does.

 

Do the heater core lines have a plastic flexible shroud over them? I think I found them if they are next to the battery. Is there an easy way to unplug them? It's like 35 degrees here and i'm working on this car outside. Any additives I can put in to help break this stuff up?

 

Yeah this definelty sounds like a backed up heater core! I quit my job at a vw dealership in service last year but I still remember my **** and we would see this pretty often. On older Audi's and VW's when you change your coolant you cant use chemicals to clean the system (unless you are good on regulary flushing the system)! Most people never do it and the years later decide its time, well there is so much **** in your system it is bound to clog your heater core. If your gunna change your coolant you gotta drain, fill with water and run it then drain the water and fill with cooland and water. As for what you do now I would suggest taking to a dealership or a shop you trust and have them back flush the system. It typically works to brake the clog free, but from my experience 70 percent of the time it will clog up again because you have already braken that **** free and typically it will clog. And agian from my experience most people have to end up replacing heater cores... very expensive. But start with back flushing and DONT use any more chemicals to brake the clog free cause it will just brake more stuff free in your system typically making the problem worse. I would not suggest touching the heater core yourself! With how hot then cold the core gets it make the nipples on the heater core brittle, and most people will end up braking them off when they try to take the lines off.

 

brown coolant sounds like someone mixed pentosin and another brand, which can cause it to gel up, which would clog your heater core, among other bad things. i would bring it to the dealer or a GOOD audi mechanic (not jiffy lube) as suggested and have them fix it for you. theres too many expensive parts that could have been damaged for you to tear into it yourself without knowing what your looking for.

 

Any idea how much a backflush at the dealer costs? I really hope they don't try and make me replace the heater core.

 

To anyone who searches and is interested. Molle Audi in KC, MO told me to flush out the heater core would be $450 IF it is not that bad.