I just got my 85 iroc 305 h.o this pass summer and it seemed to run fine. I put on headers and full exaust, then I started to notice that the temp gauge goes almost all the way to the top before it cools down happens if I am driving or sitting. Now that it cold out I dont drive the car as much but when I do it take a very long time to warmup and the heat doesnt blow out hot air. I have tried to search but cant find info. Any help would be awesome

Thanks

 

First and foremost: Don't trust the stock guage as an accurate indication of the actual state of nature at the end of the sensor. Use a separate method of measuring to verify.

If it's not warming up and blowing heated air, check the condition of the heater hoses and heater core. Ensure coolant is flowing through. A blockage could restrict flow.

If all's good there, check for the presence and proper operation of the thermostat in the water neck. Opening too early will significantly delay warm-up in cold weather.

 

I would check your heater hoses to make sure they aren't leaking. Also, is your coolant full in your radiator or is it low. That could cause it as well. Temperature gauges aren't always accurate. Also, if your thermostat is open it could cause your car not to warm up. To check your thermostat if it is bad. Start the car up when it is cold, then open the radiator cap and look inside. If the coolant starts to circulate immediately then your thermostat is bad.

 

check your thermostat