it seems that my 97 has decided it wants to be a headache becasue now when ever i fix one thing a new thing pops up. well part of the problem has been ongoing. i filled the cooling system up and got out alot of air and it stays somewhat cool. i replaced the thermostat a few months back and about a year ago i flushed the system. now that just got my car back together the heat works for a few drives then slowly gets cold. also i can have some heat coming through just the heater go to defrost it then gets ice cold then when i go back to the heater it takes a while to get heat back and after a while no heat at all. also my fans are not kicking on when the car comes up to temp. i replace the sensor in the water pump and i replaced all the relays. my question on the fans is what temp are the fans supposed to kick on? the car runs about 190 all day but when it sits in traffic it then jumps right to 210. i then have to kick onto defrost or ac since that will kick the fans on.

 

Im not sure on various differences between the B-Body programming vs the F body programming. But i know for the Impala SS and its partners, the temps run high before the fans kicks on. That being between 212-235, 240 degrees f. HTH any.

 

The fans are supposed to come on at around 220 degrees. The engine is designed to run hot.
As for the heater,once the engine is fully warmed up the 2 hoses going to the heater should both be at the same temp as the radiator hoses. If they are running cool, then the heater core is clogged. If the hoses are hot, then some of the air doors in the AC plenum are not working properly.

 

Fans kick on at
226 for low speed
235 for high speed