This should have never happened at 65K miles. The spring did not get hot, and the engine was not under a load. I was idling while following farm equipment, and when I went to accelerate to pass the engine had stalled. When I tried to restart it was obvious that there was a major engine failure. Because I was at an idle, the piston was only scratched, but the valve was bent. The repair was only $500, but this was parts only, labor was done by a friend.