weird overheating problem

[mpj76]

My false overheating problem went away after I removed my sending unit (top of manifold) and used sandpaper to remove all the buildup from it. I guess the buildup acted as an insulator, causing the electrical resistance to vary, thereby giving false readings. My guess. A loose ground somewhere or weak charging system, bogged down by accessories (such as a fan blower motor - you said it was cold out) could possibly also vary resistance in the system. Electrical problems really suck. Hopefully it is just something simple like the thermostat.