So my wife drives our Tribeca 06 and she noticed that the temperature gauge was rising (but never red lined) while driving down the highway (in winter time). So we took it in thinking it would just need a thermostat replacement. Well they replaced the 'stat' but that didnt' help. They said it looked like the coolant had particulate matter in it (like large pepper flakes). They asked if we had had the coolant flushed. We had...by our subaru dealer. So they thought the problem might be in the head gastket. They had the head sent away to be looked at under high pressure conditions and it was not a problem. Oddly enough they were saying that one side of the motor was running 30 degrees warmer than the other side but had no explaination. They replaced the coolant and ran the car for 15 minutes and had the coolant sent off for testing. Apparently, it had a lot of exhaust gasses in it suggesting there was something wrong deep down in the engine....result....alot of hassle and we are now having to replace the engine. Has anyone else run into this problem. We have taken very very good care of this car and we are at a loss to figure out what is going on...and apparently so are our local subaru dealer and the subaru corporation as the dealer has been in contact with the "main" engineers. So I would love to hear if anyone else has this issue.