[s-cars] Oil Plug removal -> Dynamite required

[Dave Forgie]

Tim:  The plug and oil pan are dissimilar metals, e.g. steel and
aluminum.  As a result, they set up a Galvanic reaction that
(apparently) corrodes the threads (sort of welds them together). The
plugs are/were always difficult to remove, even with regular oil changes
(from the bottom).  If some Audi mechanic got "smart" (may be an
oxymoron, I don't know), and extracted the oil through the dipstick with
a pump for over 140,000 miles and your plug looked brand new, then it
would have been VERY very corroded to the pan.

If you had asked earlier, my suggestions would have included:  Starting
with a cold engine  (hot aluminum expands more than steel and therefore
adds to the "grip" on the threads),  wacking the plug on the flat bit
(head)  with a BFH to see if you could jar some of the thread corrosion
loose before you started, using ONLY a 6 point socket (to cut down the
rounding problem with a 12 point) and using a BF breaker bar (or air
wrench) to you aren't trying to just "scare" it off.  At this point,
with a rounded plug, if you could cool the area (both the plug and the
pan) with dry ice or something similar, the plug should shrink and the
pan hole should get larger.  If that doesn't work, you may have to drill
the plug out (avoiding the pan threads) and/or use an "easy out" (now
there is an oxymoron for sure).

Ugly situation. But you are not the first. The cars should have had
Fumoto valves from the factory.

Dave F.