97 Jetta GL MK3 2.0L engine<p>The quick question: How do I backflush the heater core? I was told to take off both hoses at the firewall and stick a garden hose in the 'exit' hose.. which hose is that? Can someone please give me step by step instructions on how to flush it?<p>The long question:<br>For a few months now I've had a pretty bad coolant leak around my radiator. For a while I've been just filling the reservoir with water almost daily (avg temp outside was 60 degrees while using water). My engine has also not been heating up all of the way when it is cold out (40-60 degrees) but my vent heat did work. I was going to replace the radiator, but decided to try the 'stop leak' stuff. <p>I put that stopleak (i think it was 'liquid copper' or something like that) in my system about 2 days ago. The leak seems to have stopped, but now the engine still does not heat up all the way and there is absolutely no heat coming out of the vents. I went to the parts store to get a thermostat and the guy there told me to try the backflush thing. <p>Any other ideas or suggestions?<p>Thanks!