First I want to say sorry if this is out there already. I have searched and have read many posts and haven't found my answer yet. Hoping to get some clarification.

I have a 2004 cabriolet. Not getting heat. I have bled the system of air but still don't have heat. I found one thing on google about a bulletin that came out talking about a leak from plastic plug near thermostat housing. And that it could bring in air after you bleed the system. Which would constantly keep air in the system. But I have tried to bleed it repeatedly and don't seem to be getting any air out now. So I'm not sure that is the issue. One clue I have found is when I open the reservoir top it doesn't seem to have pressure after the car has been running. It always hissed before. I also have felt the 2 hoses going to the heater core. The bottom one is hot but the top one is not. I thought they should both be hot. The thermostat was changed 2 years ago so I didn't think that would be the issue. Anyone have any ideas?

sounds like your radiator is clogged. HAve u done a flush of the system yet.

check this thread for some other ideasCLICK HERE

seems like a good heater core flush can solve a lot of heat problems

good luck

Thanks for the responses. I flushed out my heater core a couple of years ago but only used a garden hose. Will try the SNO BOL stuff this time.

Based on this assessment, you have no/low coolant circulation through your heater core. You can either try the SNO-BOL & compressed air flush method, or replace the heater core.

The reason all the B5 owners try the flush first is because it's cheaper, and replacing the heater core involves removing the entire dash.

On the B6, it's possible to change the heater core without removing the entire dash. In fact, it doesn't look too bad at all. Here's the DIY.