Here's my experience as well as a photo showing where the plug broke.

E300TD glow plug stuck/broken

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles

It's not the best photo to show the breaking point but here it is:



The shaft is broken about 1/2" into the socket. In this instance, the socket, threaded rod and washers were used as a pulling tool. My biggest problem was the fact that some had gone ahead of me and tried to drill it out, runining the threads and dang near making it impossible to get hold of the GP.

A lot of progress has been made in the last year or so with the DIY removal process and it seems less likely to break one when using the procedures outlined by the folks here.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250