Will standard steel nuts weld to glow-plug bodies? I have one very solid glow-plug and I have prepared a large nut to fit over the body with the intention of welding it tomorrow. If it fails I'll have to take the head off to get the plug out.
Any experience of doing this very welcome.
Cic.
Yes
Be aware that the thread sometimes come out with the plug.
what vehicle is it ? i did a Mondeo diesel couple of weeks ago, couldn't get a glow plug out,seized solid, actually i ended up with the top half of the glow plug as it snapped and left the bottom half in the head, had to take the head off in the end, the glow plugs are too far down in the head to try & remove it any other way & what a bastard of a job it was to remove & refit the head ! what should have literally been half a hour job at the most turned into about approx 9 hours.Customer was well chuffed.............not !!!!
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It's a Peugeot 306 and I'm encouraged by the confirmation (from Duncan Wood) that the plug is actually weldable. I'm also a bit worried at the prospect of removing the thread from the head along with the remnants of the plug. However getting the plug out is the main thing so any peripheral damage will have to be dealt with once the plug is out. I'm not looking forward to taking the head off for such a simple job but like you I'll do it if necessary.
Cic.
If you're carefull/lucky you don't need to take the head off,
There is a very expensive kit to do this or
Recoil, WTI & Armstrong all make piloted spark plug repair kits (the normal kits don't have a pilot, you pays your money, you takes your choice, I've always done sparkplugs without one, glowplugs make me more nervous), odds are your local motorcycle repairers has a kit already if you don't want to buy one.
========================================= Many thanks for the information, although I hope it doesn't come down to surgery. The car is a spare that I'm preparing for future use so there's no pressure to get the job done quickly. I'll see what success I have with the welded nut and take it from there.
Cic.
To be honest they normally come out fine, just check the threads before you torque the new one up & if you do use anti seize don't overtighten it, it's much easier to strip it.
Is one plug down causing the car to fail to start? My 306 went for months on 1 plug (previous owner had rounded it off so I couldn't get it out) and it started just fine, even in the winter on biodiesel. I eventually got round to changing it after I bought a deep hex socket.
Many thanks for the information, although I hope it doesn't come down to surgery. The car is a spare that I'm preparing for future use so there's no pressure to get the job done quickly. I'll see what success I have with the welded nut and take it from there.
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========================================= Thanks for the information, BUT..
The deed is done, resulting in abject failure.
I welded the prepared 19mm nut onto the plug body quite easily and allowed it to cool. Then came the moment of truth. A long 19mm spanner on the freshly welded nut and steady pressure until something finally gave. Unfortunately what gave was the plug body shearing off the threaded bit leaving the threaded section firmly in the head and the rest (including recently welded nut) rattling around rather pointlessly.
So, time to ponder what to do next.
Cic.
========================================= It starts OK with a squirt of 'Easy Start', so it's not a non-starter. However, I do like to do things properly and it's now well past 'deep socket' time - see my other post.
Cic.
next stage is drill a hole in it and hammer in a torx bit, I would try to undo it when stinking hot. My sister's 306 kept starting even when only one plug worked, a bit reluctant with only one I agree, but they do start ok on three. (unlike my bedford cf which will not start if just one fails)
========================================= There's a minor problem with this approach at the moment because the central electrode snapped off flush (almost) with the surface of the threaded section which is itself flush with the head. I'm thinking of a way to weld something to the end of the electrode to lever it out. I might also try a spot weld bit to try and get some space around the broken electrode. Time will tell.
Cic.
the electrode should come out with out too much trouble. work out from another glowplug how much you can drill in without risking damage to the head, even do some experiments with a glowplug on the bench in a vice to see what will be best. If you can, then use left hand drill bits, snap on sell them and they are not exorbitant, that way all the forces are trying to undo it rather than do it up further.
Well if it won't start on three then it probably needs the valves doing anyway. If it will start on three then tape the connection to the glowplug up & ignore it, you can get them out with a left hand spiral drill, but unless you're prepared to take the head off when it goes wrong cut your losses.
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Yes, I think that if I can get the electrode out it's plain sailing so I'll persevere with drilling etc. From the new plugs I have it looks as if the whole electrode is a press fit in the body rather than part of it so I'm hopeful. Thanks for the suggestions.
Cic.
========================================= Well, I'm assuming that the mangled plug wasn't working so it should still start. I'll try in the morning and see what happens. I think it's pretty certainly gas-tight given its reluctance to come out!
Cic.
Well some care with a 5/16" LH drill bit should work. But there's always a possibility of dropping the end.
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Even that might not be a total disaster as it's steel and could possibly be fished out with a magnetic probe. In any case it's going to be 'suck-it-and-see' job from now on. It's tempting to just leave it provided that it starts reliably, which might be the case with as many new plugs as possible.
Cic.
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