The audi gods must hate me, busted heater core.... Need some info...

[zandrew]

The weather has finally changed and the sun was nice and warm today. I decided to bring the Audi out since I have been driving the dreadful RSX. Turn the key and she fires right up, sounds good. Take her for a spin and I notice my coolant light is on. I remember the last time I drove the car it would come on intermittently so I pop the hood and WTF, NO ANTIFREEZE IN THE OVERFLOW!!! I am guessing it's the heater core since there has been no smoke, no leaks, and a dreadful steel in the cabin and some fogging.

My questions are on the process of replacing this SOB. I have looked at some threads and it seems to be a toss up if I need too drain the freon or whatever it's called today. Does it need drained? Is there any other thing that could have possibly done this? How long will this take? Any other things I need to replace while in there?

Thanks in advance...

[FU5E]

did you check for a leak elsewhere yet? that rear flange in the back of the engine is a real POS ive replaced mine and it still leaks. I would check everything before trying to tackle the heater core.

[crazexr7]

To change the heater core you absolutely need to drain the freon. Take it to a shop so they can vacuum it out and dispose of it properly. It may also be a good time to order a new AC drier and replace that as well. Any time the AC lines are opened up the drier usually sucks in any moisture in the air, and they're usually a good thing to replace ever number of years.

[zandrew]

First place I looked was the thermostat. Its dry. I am unfortunately pretty sure on the heater core. But I plan on checking it out 100% before jumping into this deal.

[Wrath And Tears]

If it is the heater core then you should find your carpets soaked in coolant, unless its the posts the heater hoses connect to, then you can visually see the leak and it will leak on to the ground, so I guess that's ruled out.

I would suggest filling the coolant reservoir with water and looking for where it comes out, including checking your carpets for water. If you can, purchase a coolant pressure tester unit to help.

You can always bypass the heater core to verify it is the issue.

[pgiuliano98]

My heater core blew in my 2.8 in December. I bypassed it with a rubber tube for about 3 weeks, ordered a new one from ECS, got the freon drained, and replaced it in 4 days while working on it for about 2 hrs a day. This was right after Christmas too so the cold didn't help.


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[elduderino200]

My heater core blew in my 2.8. Replaced it in 4 days while working on it for about 2 hrs a day.

I did almost exactly the same. Though mine was october, so a bit warmer.

OP: yes you definitely need to get the freon drained.
I did the heater core a while back and wrote a bit about it on another forum. It's not a DIY or how-to in that it gives helpful steps, but you can follow along my progress http://www.audiforums.com/forum/b5-m...-doing-200903/
On page #6 I got it back together and did a small writeup
Good luck! It's not fun, but it's not physically demanding aside from dropping the steering column. Just a lot of taking a bolt out, remembering where it went, and repeating. Take LOTS of pictures!

[noob5]

These links may help:

http://www.audizine.com/forum/showth...e-from-passat)

http://audi-diy.blogspot.com/2007/10...core-swap.html

I do not envy the task you have in the near future.
Heater cores jobs on the b4/b5's suck. I've done three so far in my years of owning Audis (once on the b4 and twice on my 2.8 b5).

Word of advice, get the all-metal heater core from the VW Passat (part #8D1819031C). it fits perfectly, and is supposed to be pretty solid considering that they have metal end tanks vs. the plastic ones that comes in our b5's.

Good luck!

[zandrew]

I bought a 2001 avant and drove it 4 hours home. When I bought it the floor board was soaked and the seller told me the guy that cleaned the car spilled a bottle of cleaner. It did smell like cleaner. I got it home and next day the hg blew. The screen was dead and I now realise they fuqd me. The heater core was completely dead.

My blower motor has been working intermittently as well. I guess I need to dive into it as well at the same time.

Thanks fellow audi bros.

[redline380]

If it is just a summer car, maybe consider permanently bypassing the heater core?

[Avant Nate]

Before you go all crazy and rip out your dash, pressure test it. My allroad had disappearing coolant and it was just the reservoir cap not holding pressure.

[zandrew]

Before you go all crazy and rip out your dash, pressure test it. My allroad had disappearing coolant and it was just the reservoir cap not holding pressure.

My luck is completely different, it's probably going be everything that the anti freeze touches.... when I drove the car last night and stopped I pulled the cap while it was running and it made some crazy sucking sounds when I opened it. I will check it out though. I planned on bypassing temporarily until I get time to fix it.

Redline my plans was to swap most of the swappable goodies over to my avant and keep this car as the work car/ beater.

[pgiuliano98]

That sucking sound was probably because the coolant lines are pressurized.

If it's going to be a beater I'd seriously consider saving yourself the headache and permanently bypassing it. If it gets a lil chilly out just bundle up.


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