There are a few things that you should check it you CPU is overheating with one of our air coolers:
1.Reseat the cooler onto the CPU heat spreader, and make sure there is sufficient contact between the heat plate and the top of the CPU. Also make sure you are using a modest amount of thermal paste that is uniformly applied.
2. Make sure the protective film on the heat plate is removed.
3.Look over the heat pipes and make sure there doesn't appear to be any damage to them.