Packard Forum Index » Pre-War (1899-1942)

While driving my 41 120, I have the problem of the engine shutting off after running for about 15 minutes. It will start again, but die in 30 seconds. I rebuilt the carb. but that didn't solve the problem. I noticed that the manifold heat control valve was stick in the up position. Could this be the problem? Any suggestions will be helpful

It certainly does not help and leads to overheating and maybe burned valves in a worst case. Whether excess heat or something else is causing the engine problem is a guess.

When the engine heats up the thermostatic spring loses tension and gravity pulling on the weight lets the valve open. When open the weight should be in the down position so I would suggest freeing the valve and see what happens before starting to troubleshoot other causes. Coil failures due to excessive heat are a well known cause of intermittent engine shutdown problems.

A lot of folks just pin the valve open, it is rarely needed the way these cars are driven today. That would be a good interim fix and help you to troubleshoot if you have any other problems.

How is the ignition system? This sounds to me like classic coil failure.