KBNYA4

I have 2001 A4 2.8 Quattro.

I have had my timing belt and thermostat and water pump change 4 months ago. I have no heat, when I first turn the heat on you can feel the heat then it start blowing out cold air.

I have read many DIY on Heater Core. One is particular I want to follow:

Heater Core Flush | AudiWorld


I am a lose on how you suppose to get flush the system. I understand about hooking up the tubing. How am I suppose to flush the system? This article mention turn on the water flow not sure I understand that correctly. Do they mean hook up a water holes to it.

If someone can share some light on this process to help me understand clearly I will appreciate it.

Thank you,

Articus

Yeah they basically mean put a hose in the left side and use gentle water pressure to just flush it for a couple minutes. The heater core is pretty tiny.

This is literally what you are flushing out:




New on the left, old on the right. Note the two nozzles are the things sticking out of your firewall

clancy

If you search this forum for heater core problems you will find quite a history. This particular link is the best.
https://www.audiworld.com/forums/a4-...2860332/page2/
Old School Audi tore apart the heater core and showed why this vintage A4 has issues. I think this particular thread should be a Sticky.

KBNYA4

Thanks Articus for the clearing this up for me. Greatly appreciated

Thanks clancy will review the link.

KBNYA4

Articus I have a few questions. When I flush the system will I need to put G12 back into the car? What is CLR and where can I get that from? Will I need to flush the right side or only the left side. Sorry for all the questions.

Thanks

Articus

Some people have had success flushing and then using basic antifreeze (Prestone etc). I would personally just go get another bottle of G12 from VW or Audi ($27). You won't have to deal with it for atleast another 40,000 miles or up to 100,000 miles depending on how much of an enthusiast you are . Mix 50/50 with Deionized or Distilled Water. You'll need ~2 Gallons to refill an empty system.

Whatever goes inside the left nozzle will come out of the right side nozzle and vice versa. The logic is that coolant pumps into the right nozzle when the heat is on and comes out the left nozzle therefore any sediment in the coolant will get trapped in the fins on that side. Pumping in the reverse direction (into the left and out the right) is the best way to remove any sediment. Then just do it in the right direction like that link said to double check cleanliness.

KBNYA4

Thank you very much.

Dolamite

Don't use prestone ****t. I promise you'll f up your car. Stay within audi spec, the coolant is for your aluminum engine components. No tap water! If you heater core is clogged up, most likely the prev. owner(s) used tap water and/or it's never been flushed(Audi says it's lifetime...BS).

CLR is the same as lime away. Technically it's a solvent used for oxidized metal and finishes.

Picture eggshell growing in the surfaces of your heater core and that's what you have. Sometimes it's better to change it outright. Good luck man

KBNYA4

Thanks guys I will be doing this come the weekend for sure. It's starting to get cold in the NE.

KBNYA4

I completed the flush of the system today. There was a lot of whatever that came out that did not look good. The fluid was dark orange.

After I completed the flush I put some G12 back into the system.

I waited about 3hrs before I drove the car. To my surprise there is still not heat. What else could be the problem?

Disappointed....

Thanks