I have a 2004 STI with 88,000 miles on it. It has run great until today. I live in the mountains west of Denver and was driving to Denver today. I have to climb Berthoud Pass ( which is always a lot of fun). I was almost to the top when suddenly had no power. I was turning about 5,500 rpm and had been running the engine pretty hard when it happened. I stopped at the top and looked at the engine compartment. A small amount of coolant looked like it had come from the coolant resevoir. I noticed the coolant resevoir was full and it looked like air bubbles were coming from the bottom of the reservoir. The engine heated up close to the hot mark on the gauge as the engine was idling while I was looking at it. Could not see anything that looked out of the ordinary. As soon as I started down the other side and all the way to Denver the engine ran in the normal heat range. When I would try to accelerate the boost gauge would go from a vacuum to 0, but no boost from the turbo. If anyone has any ideas on what could have happened I would be very appreciative.