289 Not Warming up

[Rmoore45]

I have a '66 289 in a '67 coupe. With it getting colder in Texas I would like to start using my heater, however the engine takes for ever to hear up. I recently changed the radiator to an aluminum one but I'm still using the 180 deg. thermostat. I have a mechanical temp gauge in my car and it takes a long time for it to start climbing up to 180. I'm using a classic auto air a/c and heater setup and it worked great last winter but now the heater just blows out cold air. I know the valve is open to the heater and the a/c compressor isn't on so what could be the problem?

Thanks in advance

 

[robbz28]

Maybe your thermostat is stuck open....or it could be stuck closed and no water is passing by your sending unit....i don't have a thermostat in my 289 and my car won't get over 100 when im cruising on these cold days (the old one froze shut and i didnt replace it, just removed it, need to get one back in there)

 

[Realmongo]

How old is your heater core? It could be plugged up with years of cooling system sediment.

 

[Rmoore45]

The heater core is couple years old, it came with the classic auto air kit. I'm thinking that the thermostat may be stuck open, it warms up some when idling in a parking space after driving.

 

[rbohm]

i agree that it sounds like your thermostat is stuck open.

 

[Realmongo]

i agree that it sounds like your thermostat is stuck open.

It could be. I has a '99 Zx-2 that did the same thing to the point of getting a check engine light that I traced to a bad thermostat.