glow plug snapped

[potif]

Hi Guys
put the surf into a local garage today for timing belt change and, as cold starting has been a bit lumpy for the last week or so, told them to stick in a new set of glow plugs.
All went well with the timing belt but the front end glow plug tip snapped off. I've searched the site but can't find any handy hints to get the tip out. we've tried starting the engine and reving the guts out of it (whilst taking suitable precautions to prevent tip leaving at speed) and they started to drill it out until I pointed out that the end would probably drop into the cylinder and destroy something.
So the big question is, short of removing the head, is there any way of getting the tip out (or in then out through the injector hole, though this isn't much bigger than the glow plug hole from memory)?

[Albannach]

I think drilling it out is the preferred option. This isn't your problem though, it's the garage that broke it, so it's the garage that should fix it.

[potif]

I agree with you and they will be sorting it out but having had no head (or any other major) problems on a 185,000km 2.4 surf, I am concerned that disturbing things might tempt fate. I have considered drilling a small hole down the centre of the threaded part of the plug, re-inserting it behind the tip to stop it going through the bonnet, then running the surf back and forth to work for a few days to try and dislodge it

[Albannach]

screw in a left hand thread tap
itll wind it out with luck

That won't help. The threaded bit is already out, it's the ceramic bit that breaks off.

[NiftyNev]

Exactly how much of the glow plug is left in there?

Nev

[potif]

the 32mm section at the bottom.

When I first saw it the remaining stub would turn with a screwdriver but wouldn't come out. Since then they've drilled out about 15mm of it before I stopped them.

I have a long tap which looks about the right size for the hole they drilled so I'll try and get it to bite inside the tip then maybe turn it and see if it will pull out.

Failing that, they will have to drill the remainder, stopping to blow out the swarf regularly until there is only the tip, which will obviously drop down the hole. They have a magnetic wand small enough to fit into the injector hole which may be able to remove the tip. Does anyone know how much of the tip protrudes through the other side?

[dieselboy]

Do a search with my username and keywords of glow plug. This happened to me with my 2.4. To remove it, I used a drill and the plan was to grind little by little at the tip which was stuck in the head until it was gone. This didnt work.

I drove around for months with nothing in the glow plug hole, no amount of motorway driving or engine revving like you mentioned freed this tip up.

Is the tip ceramic on the glow plug? I understood it was. When I tried drilling it out I accidentally pushed it inwards. The only options I had was to either take the head off, or start the engine. Since I wasnt going to take the head off, I started the engine and let it idle. There was no noises or anything like that. I revved it gently, and again no noises. Nothing came out of the glow plug hole which was wide open at this time.

When I replaced the glow plug the truck started and drove fine. The only thing that had happened was a valve / tappet was making slightly more noise than the others. My plan was to get it reshimmed, however three diesel specialists wouldnt do this due to the above. They advised me that the glow plug tip was embedded in the piston crown and the head HAD to come off. Eventually, go against wat I felt, I let the last company take the head off. They found NOTHING embedded in the piston crown. The glow plug had come out the exhaust. The tappet noise was a shim like I thought, and cost me £600 for nothing.

In hindsight, I should have left the engine running, got a screw driver down the glow plug hole, and gently tapped it with a hammer until it freed up enough for the compression to blow it out of the hole. Understandibly though, the same force could also suck it into the engine.. I didnt apply much force on the drill and it was pushed inwards.



p.s. the garage that took the head off didnt burp the system afterwards like they should have, so if you take the head off make sure this is done PROPPERLY. The engine got warm due to an air lock a week later but no damage was done.

[potif]

Thanks for that dieselboy. I've just been across the road to the garage and told them to drill it out, try to hook out any bits with the magnet then fit the new plug and give it a run.

I'll report any successes or disasters as they happen

[Albannach]

I'd not have told them to do anything bar fix it. Now if it all goes to rat shit, they can say you told them to do it.

[NiftyNev]

Glow plugs can and do break of in the head sometimes. Can't really blame the mechanic unless you can prove they were negligent.

I would have tried to epoxy something into the broken tip where it has been partially drilled such a a thin threaded rod, let it set, then sprayed a bit of diesel in the hole and then tried gentle outward pressure while rotating the tip.

Nev

[biosurf]

Bearing in mind I know bugger all about glow plugs but if its a broken off tip that you can see, is there no way of putting a small rod in with chemical metal or something like that on the end and sticking it to the stuck tip so you can get it out?

Sure there may well be very practical reasons why this isn't feasible


EDIT: What he said!

[NiftyNev]

EDIT: What he said!

A bit weird, that.

Nev

[dieselboy]

Can anyone confirm what the tips are made of? They were not shiny at all and i think they are ceramic.

[dieselboy]

In reference to putting a rod in, you probably have two inch depth to go before you would reach the tip of the plug if not then more. I was worried about inadvertently epoxying the tip to the head. There is no way of seeing down 'hole.

[biosurf]

A bit weird, that.

Nev

I'm just pleased it wasnt an entirely stupid idea Chemical metal is my second favourite thing after duct tape