Using heat on stuck things

[Dan Cordon]

First off, I often use heat to get stuck things unstuck. In general,
it's quite helpful.

Just to present a different view though, I will say the effectiveness of
it depends highly on the geometry you're dealing with. For most things
found on your car, heat generally causes it to expand. So, when you have
a nut that won't come off, a little heat will cause it to "grow" a
little, making it possible to get it off.

However, consider this situation.....You have a large, thick plate with
a threaded hole in the middle of it. If you are to heat the area around
the hole, the expansion of the material will actually cause the hole to
get smaller!

Often, heat doesn't help getting an O2 sensor out depending on the
geometry. If it's threaded in to a cast manifold, you have the problem
of the hole shrinking with heat. However, if there's a 'bung' (AKA -
Threaded Bung Hole) welded on to exhaust pipe, heating the outside will
allow it to expand.

Just some food for thought. Have a great holiday, and enjoy the quattro
weather.

--
Dan Cordon
Mechanical Engineer - Engine Research Facility
University of Idaho