Ok, I got a BJ70 with 13B-T. I have a second water temp gauge that is pretty accurate. Now, when it's like below -25C and I am idling the engine at around 1100rpm, I show a water temp of about 130F. Then when I start driving, the temp goes down. Why? Also, I have the radiator totally blocked off, the grill covered, and beneathe the engine covered from just behind the radiator to the transfer case mount. I know that the bottom engine cover does not prevent any cold from getting into the engine area, but it should help to reduce any wind chill and alot of cold air to come up around the engine while driving. What would be symptoms of the thermostat stuck open and closed?