Quote Originally Posted by K9 48 Chevy View Post
I have a 40 ford coupe with a 350 and a aluminum radiator with AC/Heat combo. In the summer I had a slight over heating issue so I removed the mechanical fan and replaced it with a Walker electric fan and it stoped over heating. Now that its cooler outside (northern California) I cant get the dang motor to stay warm. When the car idels for a few min it will get up to 190-200but as soon as I take off down the road, the motor cools off to about 170 and I cant get any heat in the car. Any suggestions besides changing the thermostat ? My only guess is the thermostat is getting stuck open. I really need some help on this as I take the kids in the car and drive it everyday. Thanks a ton for any suggestions. .
I had this same issue with my daily driver, an explorer. I tried about 4 different thermostats. I finally discovered that the "high performance" one is known as a sleeve type and the regular type is a poppet style. I got a Mr.Gasket sleeve type and it made all the difference in the world, the "inexpensive" robertshaw brands are all poppet style and they are either open or closed, the sleeve type will modulate itself and it will also outflow a poppet style at wide open. See if you can locate one at summit or your local auto parts supplier, it will be more expensive but it's worth every penny.