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Spark Plug Stuck! Help!!!

6K views 18 replies 10 participants last post by  reyesz3 
#1 ·
Hi Guys,

I bought an mx5 with a spark plug stuck in cylinder 3 (without my knowledge) when i serviced the car the plug felt extremely awkward when trying to break loose.

As best i can describe the feeling is if you twisted a rubber tube within a metal tube and it creates that squeeky tight feeling ( :whistle:) anyways i concluded it must've either been seized or cross threaded. Either way there was no way i was getting it out, i even tried spraying some wd40 down there. Tbh i didn't feel comfortable enough experimenting ways to break it loose as i didn't know how long it had been there, or how long its been stuck. I could easily snap it by exerting further pressure. I thought sod it, its working fine atm, the engine is producing a very healthy amount of power and there doesn't seem to be any misfiring at all so i'll worry about it further down the line, i just wanted to enjoy my mx5!

Well...

Now the time has come where i need to seriously be worried. (well I did have it coming! :wallbash:) Whilst driving down the motorway to pick up some parts, the engine suddenly lost alot of power after i exceeded 4k. I slowed down and i could hear the engine misfiring. I popped open the bonnet and noticed the ignition lead had popped up slightly, I took it out and saw this...

IMG-20150526-WA0003_zpshr4b0qko.jpg


It melted the bottom half of the lead and now the end is melted to the spark plug itself...

IMG_20150526_184827_zps2m1aauig.jpg


IMG_20150526_184900_zpsgqenjeb9.jpg


The top pic is the one melted and the other is just to compare the difference so you know what i'm referring to.

I need some serious help guys, i know i left it too late but there's gotta be something!

I would be really appreciative of your input i really dont know what to do atm :cry:

Thanks in advance guys
 
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#3 ·
If you want to make life slightly easier then you could remove the cam cover for slightly better access - but be ready with a replacement rubber gasket and some gasket sealer for a proper job. As said, pick all the rubber crap out and make sure it's all out before you pull the plug, otherwise all kinds of crap will fall into your cylinder.
 
#4 ·
The only way to get them out if pick out all the melted rubber with a long picky tool Then get a proper spark plug socket on there with something that isnt wd40 as its about as much use as pissing on it.
I've tried picking out the melted rubber however it seems its melted to the actual spark plug. so if i try and pick it out its causing the spark plug to move with it. I can see it spinning with the rubber, but only moves a quarter turn left and right. I dont want to yank on the rubber as i might pull the top of the spark plug off with it, if its already cracked.

If you want to make life slightly easier then you could remove the cam cover for slightly better access - but be ready with a replacement rubber gasket and some gasket sealer for a proper job. As said, pick all the rubber crap out and make sure it's all out before you pull the plug, otherwise all kinds of crap will fall into your cylinder.
I think pulling off the cam cover might actually help, as there is a lip around the spark plug which might help lift off the rubber.

What would you guys suggest using to lube up the spark plug?
 
#5 ·
Snapping the top of the plug of will actually make it easier as it should come up all together. As long as the base of the plug where the sockets fit is still in one piece 9you wont be able to snap that with a picky tool) then you can get the tool straight on to that.

Plug gas/freeze lock gt85 all do a far better job than wd40.
 
#6 ·
The spark plug itself is probably not all that tight, hammer a plug socket down to smash the rest of your old HT lead to bits then hoover out the broken bits before removing the plug, replace leads with a Jackson Racing set from Moss Europe.
 
#7 ·
Snapping the top of the plug of will actually make it easier as it should come up all together. As long as the base of the plug where the sockets fit is still in one piece 9you wont be able to snap that with a picky tool) then you can get the tool straight on to that.

Plug gas/freeze lock gt85 all do a far better job than wd40.
Ahh im not too sure about snapping the plug :L

I've seen freeze lock a couple times, i might give a try and let you know about the results.

The spark plug itself is probably not all that tight, hammer a plug socket down to smash the rest of your old HT lead to bits then hoover out the broken bits before removing the plug, replace leads with a Jackson Racing set from Moss Europe.
There's definitely something wrong though, it feels extremely tight when trying to undo. It feels like the plug is biting into the thread. I've actually ordered them a couple hours ago :thumb-up:

If i do snap the plug, please pray for my soul
 
#8 ·
I can`t really see how you can tell it is tight, you cannot even see the hexagon of the spark plug itself yet, once you get the rest of the broken HT out the way it should come easily, worst case it will need Heli-coiling.
 
#9 ·
I can`t really see how you can tell it is tight, you cannot even see the hexagon of the spark plug itself yet, once you get the rest of the broken HT out the way it should come easily, worst case it will need Heli-coiling.
I previously tried to take the spark plug out way before the ignition leads got burnt and melted. It was extremely tight and so i left it, which i'm guessing led to the lead getting burnt somehow. Im not sure, it might be seized.
 
#10 ·
Removing the burnt rubber and spark plug isn't going to be too much of a problem.. A long thin robust screwdriver will do the trick but it looks like the ceramic top half of the plug may break off in the process. Breaking the ceramic isn't going to stop you undoing the plug as the hex for the socket will still be in place but the major headache is making sure all debris is gone before you undo the plug as you don't really want any crap falling into the cylinder when you remove the plug. A compressor would be handy to blow the crap out. I had a similiar problem when I broke the top half off a plug and had a few bits of ceramic left in, didn't have a compressor back then but being Chinese helped as I used a bit of chewing gum stuck onto the end of a chopstick to get the ceramic pieces out before I removed the plug.

It might feel a bit daunting but it isn't as bad a job as it looks. Rubber burning onto the spark plug isn't going to make the plug harder to undo as plugs hit much higher temps all day long. Just make sure you don't leave any crap in the hole when removing the burnt rubber and make sure the socket sits onto the plug properly before you start undoing as rounding off the hex on the spark plug will give you more grief than the burnt rubber!!
 
#11 ·
Just read you last post about trying to remove plug previously. Make sure that the hex on the plug is in good order and the socket you're using is a decent quality, make sure it's a proper six sided plug socket and not just any other deep 12 sided socket. Did you use s 3/8 set or 1/2 socket set? You might just need a slightly longer bar to get a bit more leverage.
 
#12 ·
I'd personally leave the cam cover on as it is, as that's creating more work for something that won't require it. Just get a spark socket on an extension, and hammer it on. Then pull it off and get a air blower on an airline to blow it out. Make sure you get all the debris out, might be worth putting a small hoover head down there if you've got one. Once you're sure it's all clean, hammer the socket back on and hope for the best. In theory it should come out no problem.
 
#13 · (Edited by Moderator)
When I rebuilt my engine, I had trouble getting number 3 plug out. I thought it was the same as you think; the plug is cross-threaded or stuck in the thread. It actually turned out to be the sparkplug hole was slightly smaller than the other three, (casting fault ;) ) and it was the plug spanner sticking inside the actual walls of the plug hole. It fitted fine in the other three! Anyway, I simply got an old plug socket, and ground the outside of it down until it fitted without binding in the hole.

Might not be the case with yours, but just a thought.
 
#14 ·
Remove crappy bits of HT lead left. Hoover as often as possible.

Using the old HT lead, re-wire engine back up. Warm up with misfire. Once the engine has some heat, NOT too much. Remove HT lead, and pour a little oil down the hole. It will sizzle and pop and smoke. Let the engine cool down.

Try to undo plug. If it works great, if not repeat. The capillary action caused by the expansion and then the contraction should draw oil into the threads.
 
#15 ·
Just read you last post about trying to remove plug previously. Make sure that the hex on the plug is in good order and the socket you're using is a decent quality, make sure it's a proper six sided plug socket and not just any other deep 12 sided socket. Did you use s 3/8 set or 1/2 socket set? You might just need a slightly longer bar to get a bit more leverage.
I've tried with a proper six sided socket but now that i think about NickCann's comment i dont particularly remember if the socket was making direct contact with the plug.

I'd personally leave the cam cover on as it is, as that's creating more work for something that won't require it. Just get a spark socket on an extension, and hammer it on. Then pull it off and get a air blower on an airline to blow it out. Make sure you get all the debris out, might be worth putting a small hoover head down there if you've got one. Once you're sure it's all clean, hammer the socket back on and hope for the best. In theory it should come out no problem.
When I rebuilt my engine, I had trouble getting number 3 plug out. I thought it was the same as you think; the plug is cross-threaded or stuck in the thread. It actually turned out to be the sparkplug hole was slightly smaller than the other three, (casting fault ;) ) and it was the plug spanner sticking inside the actual walls of the plug hole. It fitted fine in the other three! Anyway, I simply got an old plug socket, and ground the outside of it down until it fitted without binding in the hole.

Might not be the case with yours, but just a thought.
Wow, very interesting! I think this might actually be the problem! I'm going to have a go at it tomorrow and will update you guys on what happens with a skinnier socket. I honestly dont remember if the socket WAS making direct contact with the plug, it just felt like the socket was grinding against something, might have just been what you said about the smaller hole!

Remove crappy bits of HT lead left. Hoover as often as possible.

Using the old HT lead, re-wire engine back up. Warm up with misfire. Once the engine has some heat, NOT too much. Remove HT lead, and pour a little oil down the hole. It will sizzle and pop and smoke. Let the engine cool down.

Try to undo plug. If it works great, if not repeat. The capillary action caused by the expansion and then the contraction should draw oil into the threads.
Thanks I'll try the oil this time :thumb-up:

Thank you all for the excellent advice and tips! I'll really owe you guys one if it works and i can finally remove this godforsaken sparky!

Thanks again and wish me luck!
 
#16 ·
Finally got it out guys!

Ended up using abit of WD40 and an extra bit of force tightening and loosening a few dozen times before finally loosening it and it came out without a fight! Turns out the socket was making contact before, the hole for the spark plug is fine and it WAS the spark plug possibly seized.

Thread is perfectly fine and the car is running great again! Thank you for your help guys!! :D

IMG-20150528-WA0014_zps5jg0veop.jpg
 
#19 ·
Spark plug looks like it got a bit of water and rusted itself into place, am sure she runs great now that was a bad looking plug u took out there.
It had been sitting for a while before i bought it off the previous owner, and the brakes were seized also so i guess i had it coming. She really does run great! So happy shes running on all 4s again :D

And the moral of the story, if you have a problem, deal with it straight away, if you leave it, it won't get better, but could get much worse. Glad you got it sorted. :)
Hahaa very true, lesson very well learnt! Thanks mate :)
 
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