Heat riser

[Cooke]

I have just noticed that the door to the air filter that should open when the engine reaches operating temp, does not. Would it be better to keep the door forced in the open position (since I will not be driving it in 5deg weather) or is there a fix for this??
Thanks to all for all of the information so far, this site is great resource.

[Barry Wolk]

Does your car have the shroud that covers part of the exhaust manifold? If it doesn't the bi-metal action of the door won't happen because it'll never get hot enough to activate the mechanism.

The mechanism may be rusted, too. Post pictures, we'll help diagnose.

[Cooke]

I can manually operate the door and it looks like all parts a present but the door never opens on its own. I hope the pictures help let me know if you need another angle.

[Shelly Harris]

The '57 version is little bit different but basically the same. My flap is always in the closed position which shuts off the section which covers the exhaust manifold. Simply put, the cold air is always on. Like you I'm not daily driving the car in the winter. When your car is warmed up you want to be using the cold air input.