As a search of the archives would show, it is not that uncommon for a
head stud to snap. That is because with the VW waterboxer all of the
studs are inside the waterjacket, exposed to the coolant or whatever
someone put in there for coolant. Often times the stud that snaps is one
covered up by the valve cover. When one of those goes the coolant leaks
into the valve cover and then turns the engine oil into something like
pudding. I have replaced just a broken stud and  had the engine work
fine. Getting the remains out of the block might be a challenge. Since
you need to pull the head, check the other studs too.

Mark

jbange wrote:

> Well, it just wouldn't be Christmas unless I had SOME kind of
> catastrophic
> mechanical failure.  Driving along to mom's place, about 3 miles from
> home,
> when I hear a loud POW! Sort of halfway between a backfire and a tire
> blowout. I look in my side mirror and see clouds of white vapor
> spewing out
> the back.........Coolant was coming out of the hole located at the
> top-aft corner of the left/driver's side head-- a hole that should
> have had
> a threaded stud through it and sealed with a cap nut. The head stud
> apparently snapped and shot off like a projectile. Being only 3 miles
> from
> home I decided to have AAA tow us bcak home, get the other car, and deal
> with it later. I haven't pulled the head off yet, so I'm not sure the
> condition of anything I might find. My neighbor has a spare stud and nut
> he's offered to give me, so I'm wondering if just replacing the one
> stud is
> a good idea. .....