extracting a glow plug

[helmsy157]

Hi all, any ideas please, when removing a faulty glow plug the nut head has sheared off the threaded part of the plug. It now rotates freely around the electrical connection and I cant pull this out. At the moment it is not a problem running the engine but if I extract the electrical stud is it likely to break the bottom of the plug and hence the cylinder leaking. I dont want to remove the head if I dont have too its a real pain!! I do have the correct size drill and threading taps for the glowplug, M10 x 1.0 all ideas welcome

[zollaf]

normally the head will have to come off.

[helmsy157]

yes I know, but it might be worth bringing the piston up to tdc and then drill out the old plug and try to extract the end if not then head off. What I would like to know is if I try to pull out the electrical stud will it break out the end of the plug, or do i just accept i only have three plugs.

[zollaf]

you can only try what you can, you might be very lucky and it comes out, but 99% of the time you take the head off and knock it out.

[helmsy157]

Hi there, an update, i purchased a laser tool lookalike set for removing glow plugs, having read the instructions i tried a slightly different solution with what Zollaf had said in mind, that is to break off the stud and drilling down into the plug sufficiently for the tap supplied to thread the bottom of the plug. then drilled out the top thread of the plug to break free the base and run the tap supplied to clear the upper thread, then used the threaded puller screwed into the base and pulled out using the extractor supplied. After finding a glow plug not working, I tested all my cars for this and suprise they all had at least one not working, the worst starter had two duds. Now a quetion, does anyone know where to buy the connectors for the plugs, I know Bosch at least do these but cannot source anywhere

[AutoTDI]

After 19 yrs and 144K miles, I need to replace the glowplugs in my A4 and preferably without shearing off the nuts. I have already tried to remove the old plugs but they are really stubborn and refuse to budge. Is there a recommended technique? I have been trying with a cold engine, but should it be warmed up first? Neither the official Audi Service Manual, nor the Haynes Manual makes any mention. Furthermore, I have damaged two of the connectors when trying to remove them, so they will also need replacing.

[zollaf]

hot engine, proper piping hot. metal expands so the head and glow plug holes will be marginally bigger when hot. keep applying penetrating oil and go for it, once they crack off, work them back and forth until they come out.

[AutoTDI]

Thanks for that - just as I thought about the hot engine. I suppose I should have replaced the plugs years ago to avoid this problem, but haven't had any problems starting until recently when I became aware of exhaust smoke on very cold mornings. The engine still starts OK though. I know that two plugs are kaput, one seems OK and one uncertain until I can wrestle the connector off. I've already broken the connectors on the 2 kaput plugs and I'm nervous about damaging the last one.

Aplogies for posting in the wrong forum as I thought I was in the A4/B5 forum.

[zollaf]

ah yes, you are in the 80 section. never mind. i look at ' new posts' so it matter not to me what section anything is in. yes, the plastic on the connectors does crack and theres nothing you can do to stop it. usually thought the metal connector is ok, and this can be pushed back on, or another bullet connector crimped onto the wiring.

[helmsy157]

this is a common problem, try first to warm up the engine and spray a lot of wd40 around the plug, leave the engine to cool and if you have time then repeat, try to extract the plug when warm. Now if all fails, you will need to buy an extractor kit they cost around £20 on ebay and follow my advice re using the kit, you don't want to get swarf into the engine. The bosch connectors are available from carpartsonline I can give you the part number if you want though I have found that renault use a much better connector with a handle on the end to ease removal

[helmsy157]

]this is a common problem, try first to warm up the engine and spray a lot of wd40 around the plug, leave the engine to cool and if you have time then repeat, try to extract the plug when warm. Now if all fails, you will need to buy an extractor kit they cost around £20 on ebay and follow my advice re using the kit, you don't want to get swarf into the engine. The bosch connectors are available from onlinecarparts I can give you the part number bosch 1 928 404 879 though I have found that renault use a much better connector with a handle on the end to ease removal megane mk2 1.9dci

[AutoTDI]

Well, it's taken me a long time to sort this out and I've not had any problems with starting, but with winter approaching I thought I'd better do something. Tried warming up the engine and applying WD40 and the plugs came out easy-peasy. Just about to order new connectors. Thanks to all who gave advice.