Thermostat

[Tsi]

I had a problem with my system freezing also. I forgot that I had put water in the system in the summer and sat a couple days in -20 weather. My car's idle started out high and slowly rose, my upper hose was empty, but my lower radiator hose was slushy. I let it run and kept watching the gauges to make sure everything was in operating temps, sometimes the temp gauge would get hot, so I would just let it cool down for 15 minutes and go do it all over again until the coolant system was unthawed. Once it got in operating temps, I found out my heater wasn't blowing out hot air, so I drove it around for awhile to see if that would help. I must of drove that thing around for at least an hour and it still was blowing cold air. So I pulled it in the garage, let it sit and flushed the system and put in a 50/50 mix, and let it run for at least 1-2 hours. After that time it finally unthawed all the way through the lines to the heater core. After that experience I will always have a for sure 50/50 mix.