newly restored 39 Buick with overheating problem

[buick looks fine for 39]

Hi guys,

I've been involved in two 39 Buick Special restorations and one car runs at normal operating temperature and the other boils over constantly. In the cool running car the bypass valve was removed and replaced by a washer in the thermostat housing. The hot running car still has the bypass valve in the thermostat housing. I remember a thread where the thermostat housing bypass valve was  replaced by a washer. Could anyone give me the thread to this topic?  

 

                                                                                                               Thanks

                                                                                                                 Leif

[1937 Buick 66C]

Hello Leif,

 

The problem is, most likely, that the bypass valve is allowing coolant to recirculate through the engine instead of allowing it to circulate into the radiator.  Here's a link to an article I've passed out to many, many straight-8 owners to address this problem.  Incidentally, there is no washer involved.  Only a freeze plug with a hole in it. 

 

This link will take you to the article and related images: http://2experts.org/Vehicles/Buick/Coolant_Bypass/

[buick looks fine for 39]

Thank you Thank you,  this info is exactly what my friend needs.

                                        Thanks again

                                              leif 

[Mark Shaw]

The generally accepted terminology would be "orifice plate", regardless if it was made from a washer or a freeze plug.

 

"An orifice plate is a device used for reducing pressure or for restricting flow."