Just curious, using an infra red temp gun (laser sighted or not) - where should the gun be pointed at?
1. At the glow plug
2. Next to the glow plug
3. Anywhere in the glow plug area
Obviously from logic reasoning, the plug would be the hottest - and it will get colder as measurement is taken away from the glow plug.
So when someone has an engine running at 250F - where did they take the measurement?