I've had my outback for about three months, and I had noticed some peculiarities about the way the heater and engine temperature acted. Once it got cold, the engine took forever to warm up, and the heater would only blow hot when the throttle was open. I chalked this up to a thermostat issue, and boy was I right. When I pulled the old one out, there was nothing but the bracket! The rest of the valve assembly was gone! But now I've replaced it with a thermostat that I've tested and know that it works, and I now get no heat blowing at all and the engine overheats after a few minutes of driving. I'm afraid that there is some kind of blockage but I don't know where to begin looking. Please help save my baby!