Using Heat on Stuck Things, it works based on Physics

[Chris Thorp]

You are right that the metallic connection between the pipe and the 
sensor should transfer heat fairly quickly, but if these sensors had 
nice metallic connections, we wouldn't be fighting with all this rust to 
get these blasted things out.  :)

I'm guessing that another factor that contributes, that I don't think 
I've seen mentioned in this thread, is the differential expansion of the 
two materials "breaking up" the solid rust.  This would explain why 
something still won't budge while hot but will then come right out after 
it has cooled down.  IE: even if they both end up eventually expanding, 
they will do so at slightly different times.

-Chris
'95 A6qm

>fairly good heat conduction abilities, so the mere contact of those
>threads to the pipe may be enough to heat the sensor threads so
>that they expand too. 
>