I'm having a problem with my 94 Z28, and I have no idea what's up. In cold weather, the temp gauge never reads over 185 and I get very little heat out of the heater. When it gets nice out, the temp gauge goes up to a little over 210, and I get hot air from the heater (when I don't really need it).
The difference between cold weather and warm weather also affects my idling. While idling in cold weather, my fan doesn't kick on much. When it's warm out, the fan won't stop running.
Anybody have an advice or any ideas that would help me figure this out?

 

How long have you owned your car? It's possible the previous owner removed the thermostat, and it will take forever for the engine to heat up in the winter. When you start your engine cold, grab the upper radiator hose closest to the radiator with your hand and feel the temp. If you can feel it starting to get warm shortly after the engine is running, then you likely have a missing or stuck open stat. Coolant shouldn't be flowing through that hose till the stat opens.

 

I bought it a couple of months ago, so I'm not too sure what they did outside of replacing the Optispark, Radiator, fuel pump, and calipers/rotors. I thought about just changing the stat because it's cheap and never hurts anything. Just gauging to see if anybody else has any ideas.

No matter how long I run it in the winter, it never gets over 185 and the heater never blows out anything more than luke-warm air.

 

mine runs at about 185 all the time. ^^^ agree with 69 the likely issue is thermostat, it its gone you will find out why the thermostat was removed when new one is installed. you may have a plugged radiator