I just went to a WC setup and the first run at it was pretty ugly, but effective. I was really surprised though to find two leaks. One I new about, it was from the reservoir and was outside my case. Besides a little green stain on the carpet, it didn't cause a problem.
The other leak was from the CPU block, D-Tek fuzion. The barbs are very close together and I have 1/2 ID - 3/4 OD so it was tough to get the metal worm drive tube clamps on them. I didn't realize the leak until about a week after I set up the loop- I am putting it into a TT armor case so that it is prettier and self contained. When I took the graphics card out, I noticed the green goo on the back of the card . Obviously, the water had evaporated and left the thick coolant behind. There was also small granular, yellow components in the goo. I used distilled water from the grocer and swiftech hydrX coolant. I don't know how long this had leaked. There was a decent amount of goo, so I imagine it had been leaking slowly for a couple of days. I cleaned it with 90% isopropyl alcohol and a soft toothbrush.
I was having problems with the card in the past week. The fan had a mind of its own. The settings for fan control were missing in ATi Tool and RivaTuner. And when overclocked, the card would get very hot and crash COD4. Could this have been because of the leak? As far as I can tell, the only problem was the fan control.
I did a quick test after I put everything together in the new case and RivaTuner was once again able to control the fan on the card. I ran 3DMark, but couldn't get the score because I wasn't hooked up to the internet. It didn't crash though and the FPS on the first test seemed right.
I want to water cool the card also, but I'm not going to take off the HS until I know it is ok in case I have to RMA it (if I can). I'll have the system up again by Monday afternoon to try testing it, but I wanted to know if anyone had experience with liquid on graphics cards. Will MSI know that is why something isn't working if I RMA?
If MSI allows you to remove the stock heatsink and still RMA it with a written note you got WC liquid on it, I don't see why not. I thought only EVGA and BFG allowed removal of the heatsink and not void the warrenty. They will remove the stock heatsink methinks and be able to tell it was prev. removed.
if there isn't any noticable damage to the back of the card msi won't know what happened. they might be able to tell if they really tried, but they won't spend the time (or money!) bothering wth that. I sent a 9800pro back to ati years ago that was killed with a bad bios flash. they just replaced it, and it would have been easy to spot that one. I think if something was damaged (and it VERY well might not have) I think an rma would still work.