924Board.org

[sleepy]

decided to take a look at the condition of the spark plugs today & found the No 2 plug didn't come out as easily as it should. when i looked at it the top 2 grooves had metal in them
does this mean the thread is stripped all the way down the hole & will it cause any problems? I'v put it back in now.

-sleepy
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meteor silver 1981 924 lux. -UK

[Lizard]

was it hard to put it back in, or did it feel loose?
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3 928s,

[sleepy]

it wasn't loose. A little bit stiff but i didn't use any wd40.
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meteor silver 1981 924 lux. -UK

[Mike924]

When you say the 'top two grooves', I presume you mean with the spark plug pointing terminal cap up and business end down. If so, you've probably only damaged the first couple of threads in the head and you should be OK. But you need to go easy on putting plugs back into that cylinder, because the damaged threads in the head will make it more easy to get the threads crossed when inserting the spark plug.

You can attempt to clean the threads in the head, which will help to allieviate the above problem. Get an old spark plug (but with good threads) and file three or four, equally-spaced grooves in the threaded part, parallel to the axis of the plug. Try and get the sides of the grooves nice and square. What you end up with is a kind of 'die' for plug threads.

Carefully inset this into the dodgy cyclinder and gently wank it back and forth half a turn or so, gradually advancing it down the threads in the head until it bottoms - don't tighten it! Carefully unscrew it, making sure you catch any swarf (a drop of oil or grease applied to the plug beforehand will help with this) and clean the hole in the head with a cloth (again a drop or two of clean oil (eg 3-in-) on the rag will help here).

Make absolutely sure you don't cross-thread the 'plug-die' when doing this. If you do, you will definitley have shagged your head.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[sleepy]

no i mean the two grooves at the 'gap' end!
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meteor silver 1981 924 lux. -UK

[Mike924]

That's a touch more serious, but it's still worth having a go at cleaning up the threads; there will probably still be enough to hold the plug in place. You just need to go easy on it.

Good luck!
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org