overcooling

i have a 94 merc. tracer 1.9 and ever since i've had it theres always been a lack of heat. i used to work at a ski resort and driving in the winter was no fun in that car. so heres the thing, in the winter the temp gauge stays below the normal line and even went as low as the C line if i was going downhill. thought it was the thermostat, had it replced, still the same thing. now during the summer the needle gets to about the n line, but no higher. but while im in the city and the car idles at a stop light the needle goes to the middle, then when i get on the highway it drops back to below N. while the gauge reads at about N i turn on the heat and it comes out pretty hot, then after about 30 secs. it cools down to luke warm.

so in the winter i am always wearing gloves while driving cause its always cold. and when its about 20 degrees F or less the windows ice up INSIDE cause of the lack of heat.

BTW the heater core was replaced about 14 months ago. and also the head gasket blew in march of this year but i fixed that myself. and replced the old antifreeze since the system was contaminated.

so basically i might replace the thermostat yet again. i still have the old one which looks brand new and i tested it in water and it opens up at the right time (195 degrees). just wondering if anybody else had this problem or can give me a few suggestions before i replce the thermostat again. if you cant think of anything could you at least tell me where your temp gauge is at when its fully warmed up? thanks a million!

have you checked to see if the fan is working properly? Remember while you are driving that cold air is also blowing down the radiator at higher speeds you are making a wind chill. I know on the bigger motors we would put a piece of carboard in front of the radiator to block this wind chill. Also have you radiator pressure tested/cleaned by a radiator shop. I had a Van that acted like you mentiond and come to find out the radator wasn't fully circulating. He replaced it and the heater worked find.

that makes sense and so thats what i do during the winter. but as far as the fan, i know that it at least works. if i am at idle and i turn the heater-A/C fan to 1, the radiator fan comes on. and then shuts off when i turn the inside fan back off. and also no codes come up when i do a engine off or engine on test, except for 172 which is another story... i'll see if i can get it pressure tested, thanks! i would've never thought to do that