[Vipergrün]

If your heater valves are working correctly, the hot air should be dumping down and at speed, the air should be carried away fine, at idle, there 'may' be some heat buildup. However, I would be more concerned about the heat 'radiating' from the heat exchangers to the lower valve cover area. They make "Heat Shields" for this very purpose. The other thing you can do is upgrade your 5-blade fan to a later one, if you have a 5-blade. This will get more air moving for cooling.. Just some thoughts......