I own a 1987 325i.
Yesterday I was doing a routine spark plug swap (only been about 5,000 miles, I know they still have life left in them..). I tool all 6 spark plugs out, then went to get a set of 6 new Autolite Platinum plugs. I hand tightened them all into place, as to prevent cross threading any of them. Set my torque wrench to 22lbs and began on the plug cylinder furthest away from the radiator. Torqing, ...torqing.. it starts to get tight, I felt something may be wrong, so I set wrench to untighten it. The first crank to the left and, Snap.

The spark plug broke in half. The head of the plug, with the threads is stuck tight in place, but has no knotches or anything sticking out to loosen it.

I cant fit a socket to it, because the 16mm bolt is no longer attached to the threads. I dont want to drill it for a number of reasons, primary reason being that I would be drilling into the PVC type material in the center of the plug anyways, and would probably just get junk in my cylinder.

Has this ever happened to anyone, does anyone have some advice for me?
Thanks for your time,
David [scoutx]

get a pick and try to turn it. If it broke loose u might be able to turn it out. And if u need to drill it it is a better idea to pull the head off

I will try and use an 'easy out'
I may be able to fetch the rest out with that.

Can you hammer a sharpened large flat headed screwdriver into it (or a chisel)? Then turn it out?

If the easy-out doesnt work, thats an idea I will try

http://www.bmpdesign.com/technical/tech_tips/change_spark_plug.php

I've never heard of this happening before. Weird. Aluminum heads are serious huh....

It wasn't that bad. If anyone ever has this problem.. use an easy-out!
It costs like 4 bucks, takes about ten minutes, bamn. It's out.

thanks for the help guys