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cross-threaded a sparkplug (Now fixed )
Posted: Wed Feb 10, 2010 6:35 pm
by Roccomad78

O.M.G i gone and cross threded one of my spark plug's , i could shoot myself , I am now in a complete panic state breathing into a brown paper bag as im typing .
Does anyone know of a way to helicoil or tap this right without taking off the head , dont realy want to go down that path but also dont want aluminum shaving's in my cylinder , Also does anyone now what size tool's i will need for this job e.g helicoil size tap tool size as ebay sell's all diffrent sizes .
Any help would be a appreciated massively.
thanks Tom
Re: cross-threaded a sparkplug
Posted: Thu Feb 11, 2010 1:17 am
by Jay4424
Don't think you can "helicoil" them can you?!?
...perfect time to upgrade your head!

Re: cross-threaded a sparkplug
Posted: Thu Feb 11, 2010 8:56 am
by Brunty
You can get a Helicoil specifically for spark plugs. I wouldn't want to do it with the head fitted though.
Re: cross-threaded a sparkplug
Posted: Thu Feb 11, 2010 9:35 am
by Roccomad78
After spending hour's reading up on this , seem's the head has got to come off unless you use a backtap tool with a mandrel greased up to catch the shard's of metal , Im gonna just get the head pulled chance to change the gasket and cam belt if anything , then buy the tool's to rethred the damaged thred on the head or failing that try get a new head.
I only use this car a few time's a year in the summer, im lucky if i do 300 miles ,so its cover back on till i can get this sorted.
Thanks for the help guys any info on this matter or anyone know the tool's and sizes i need would be great.
Cheer's Tom
Re: cross-threaded a sparkplug
Posted: Thu Feb 11, 2010 5:48 pm
by Nate
i know this is a bit late, but useful for next time... screw your spark plugs in with a short bit of fuel pipe stuck on the nipple. turn it by the pipe, then if it does cross thread the pipe will slip on the plug.
Re: cross-threaded a sparkplug
Posted: Mon Feb 15, 2010 6:37 pm
by Roccomad78
Cheer's for that will take extreme care when i next mess with plug's ,THIS HAS BEEN A LESSON I WILL NEVER FORGET.
Im thinking of just changing the head rather than messing with helicoil's and back tap kit's , If i can find one ebay is dry of ex head's or engines at that ,
Thank's again Tom the rocco killa!!!! :(
Re: cross-threaded a sparkplug
Posted: Tue Feb 16, 2010 12:25 pm
by chopperoli
I had this problem on my Mk1 recently when putting new plugs in, I borrowed a thread cutter, greased it up and ran it in & out by hand a phew times. Cleaned up the threads with solvent and carefully put the new plugs in. No sweat. Try it, using grease in the cutter tool grooves should catch swarf- and any it doesn't will blow straight out the exhaust.
Re: cross-threaded a sparkplug (Now fixed )
Posted: Wed Feb 17, 2010 6:45 pm
by Roccomad78
Did what you said , used a 14mm thread chaser greased up , it is now cured :D
Thank's for all the help guy's , oli your a star
WILL TAKE GREAT CARE NEXT TIME I CHANGE MY PLUGS!!!!!
Cheer's peep's Tom