Also, instead of using a temp gun, you can put a drop of water down the cooling head on the glow plug to check the temps (just like foxy's spit test). If the water gently boils aways after 3 to 4 seconds, then you are at the perfect heat cycling temp (212 F). If the water just sits there the engine is too cold and if the water starts violently jumping around and sizzling then the engine is too hot. I never use a temp gun. A cup of water and a small eyedropper is all I use when breaking in a motor.

www.focusprinting.com