ok, what does your temp gauges read at in the winter? should it really change from the summer time? cuz mine sits right below the F symbol when i let it idle up and in the summer time, but when im driving in the winter its down to the second big dash and usually stays around there. i was just wondering if that was normal or not.

 

I'm not driving the rex in the winter due to the salt, however, I have noticed the same behaviour on almost every car or truck I've driven. In fact, on an older (70's something) Ford flatbed, we actually had to cover up the grille with cardboard in the winter when driving on the highways to keep the truck from running too cold. I still see a good number of rigs and school busses with zip-up covers in the winter. The Saturn and the Ford Ranger both do the same thing -- although they're not chilling so much as to require cardboard over the radiator! I've noticed that when the temperature dropped here, the ice-cold air flowing through the engine compartment results in a slightly lower reading on my temp guage.

The "test" that I use to determine if the car is running "too" cold is to kick the heater on full-blast after driving a few miles (when the car should be to normal operating temp). If the guage reads really high, but I have no heat: Coolant is low or gone. Gauge reads nothing and lots of heat: broken guage. Gauge reads lower than normal and low or no heat: car's running too cold. Gauge reads in some normal-ish position and I have lots of heat: Everything's probably good.

Not real scientific, but I have yet to cause any overheating damage to an engine.

 

The t-stat is at the end of the cycle (so to speak) so when it opens to let water flow out of it the water in the rad is extremely cold vs summer coming in so the temp will be a little down. The newer the t-stat the less youll see this. The older t-stats arent as reactive (old spring hot cold etc losing tension). I just replaced mine and its rock solid as it was in the summer (before replacement was cooler) New T-stat is in better condition not allowing as much to flow through. Hope this helps, not a huge concern unless its too cold, no heat from heater and choke stays on.

 

mine on my 80 LS moves just into teh white, barely above the C. my 85 GS 's moves up to the little thermomiter thing and stays there. always has since the new radiator and thermostat.