Intro: How to Remove Broken Glow Plugs
If you have a broken off glow plug, you are faced with a choice:
A: Remove the head and take it down to a machine shop to have the plug machined out
-- OR --
B: Make a simple puller to yank out the plug.
This page describes how to do (B)
STEP 1: Tools, Caveat & Initial Work
- vice grips
- drill motor
- 1cm drill bit (13/32" is just right, 7/16" might be too big)
- M6 x 1.0 Tap and drill set
- hardened M6 x 1.0 bolt, at least 6cm long
- hardened M6 nut
- assortment of washers
- a 13mm X 3/8" standard depth socket
- patience, lots of patience, heads are very expensive replacement parts
< no picture for this step ... sorry >
STEP 2: Freeing the Threads
STEP 3: Drilling the Body
(All units measured for 24 valve OM606 engine)
STEP 4: Tapping the Body
(Again, measurements relate to the OM606 24V)
STEP 5: Building the Puller
STEP 6: Pull the Plug
Reassemble the puller with a 13mm x 3/8" socket instead of the washers. The hollow formed by the socket will allow the plug to move further out of the head.
STEP 7: Success!
STEP 8: Cleanup & End Result
As an experiment, I've chosen to coat the entire body of the plug with Hylomar HPF. Aside from sealing the nose and threads this sealant is fairly temperature stable and may fill up the space that would otherwise fill up with carbon. We'll see in 50Kmiles or so.