TAZ, you need a new t-stat. You should be at the middle (straight up) mark on the temp gauge which should be around 200-210*F with a stock 195*F t-stat.

 

Then I probably need to change mine too... It doesn't get warm unless I'm driving it

Though, the fan spinning when it's idling and cold probably isn't helping warm up, lol.

 

The fan only cools what is in the radiator. When the t-stat is closed, very little of the cold coolant from the radiator is flowing into the engine. There is a bit of heat dissipation through the heater core which is being constantly circulated with hot coolant from the engine, but very little of what is in the radiator is being used and this should not affect the warm up time of your vehicle.

I know that all of the automatic climate control vehicles when in auto mode will not run the heater fan until the engine exceeds a certain temperature which is around the 1st line on the temperature gauge in the dash (~120*F). This helps the engine warm up faster.

 

will a bad thermostat cause a rough idle or anyother problems?

 

YES!

Your puter uses engine temp to control engine/tranny performance.

 

just replaced my t-stat and my 96 jimmy runs so much better faster accel. heats faster shifting seems about the same but the engine performs better.