snapped glow plug

[edthesparky]

right long story short.

bmw 525d e39

no.s 3-6 came out fine and I've replaced. no1 wont budge (unscrewed but wouldn't come out) so ive screwed back in

no.2 has snapped off. got a mechy mate coming to have a look this week sometime but im worried even if we get the thread section of the plug out, the actual probe still isnt guna move. if that snaps off im fecked..

suggestions or info anyone?

Ed

[sanchez]

Only ever had 1 glow plug seize on me before and snap. Heated it right up and hammered a torx socket into and let it harden in place, came out ok after that.


Failing anything you try, there's a spray called Metaflux that Nissan/renault use for removing the injectors on M9R engines, expensive but has only ever let us down a few times.

[boss]

i drill a few of these out a week,

its not an exact science, but i'll try and give you the gist of the technique,

BMW, i'm gonna hazard a guess at M10x1 thread,

tools required:-
Slide hammer
Drill ( cordless )
Drills
Taps

this all depends on where it has snapped, if the hex part has snapped away from the body, but is still attached to the electrode, this is good,

where the wire goes onto the glowplug if it is threaded, this is good, you'll need an adaptor that fits your slide hammer, and the thread on the glowplug ( M4 typically ) if it is a push on connector type glowplug, i have a set of mole grips with a nut welded on the back that suits the slide hammer,

wind adaptor or clamp mole grips onto glow plug, and slide hammer the hex part and hopefully the electrode out of the centre of the glow plug leaving you with the threaded body and hollow tube part left in the head,

grab a new glow plug, and figure out how far in the head the threaded body extends,

with a 5mm drill, drill down past this mark at least half an inch,

for the sake of keeping things square i do the next step as a matter of personal preference,

get an M6 tap, and run it down the newly drilled hole, as far as you can get it, DO NOT snap it off,

now, assuming 10x1 thread, your going to have to drill out the threaded section of the glowplug,

going up in circa 1mm incriments in drill size, work your way up to 8.5mm, and watch for corrosion and steel threads peeling out, i realise that the correct tapping drill for 10x1 is 9mm, but you want to stay away from the aluminium head as much as possible,

grind yourself up a chipping type tool, and using a combination of this and a plug and 2nd 10x1 tap, restore your thread,

again you must ensure that you have got all the threaded part of the glow plug out,

with the thread restored, turn back to the M6 tap, run it down the tube further if required,

fit an M6 adaptor to your slide hammer, and wind this into the body of the glow plug, and yank away! it should pull it right out,

blow out any swarf and double check your thread,

its a ballsy job, but if it saves taking the head off,

if you have snapped the head off the glowplug, and the electrode is in the centre of the tube sticking up looking at you, you're pretty ****ed, i get these out in the mill.....

[edthesparky]

thanks guys.

Boss - I'll put up a pic.

basically the nut part of the plug has snapped off and taken the top with it. whats facing me is the thread part almost flush into the block, which i think will be removable as it was loose, but the problem is with the centre part of the plug, that is stuck in firmly. it does however still sit out about an inch so easy to get something on it, as long as it doesnt snap off.. Ive been advised to leave it, leave the lead off and fire it. if its proper stuck the plug will either stay in forever or fire out under compression

thoughts on that?

thanks for your reply!

[emperor]

it is not soo hard to do.
tap and drill will work.
or buy a proper kit to remove them.