Spark Plugs - Electodes falling off!

[Phil Payne]

> > Yes, seen it several times.  The engine has ingested a small hard object
> and
> > hammered it against the plug.  Drop an Aaron Bend-a-Lite or something
> > similar down the hole with the piston at BDC and let us know what you see.
> > My money is on a forest of small circular marks - 6mm or so in diameter.
>
> Seen this sort damage a couple of times but only on VW/Audi vehicles and
> I've a theory forming but don't know if I'll ever prove it.
> Those strange marks, don't they seem to be remarkably similar in size to the
> threaded sleeve thats fitted to the top of spark plugs? And what do you do
> with the sleeves when fitting new plugs to a VW/Audi - you take 'em off and
> trash 'em.

Much too small and relatively soft.  Whatever does this is around twice the diameter and HARD.

--
  Phil Payne
  http://www.isham-research.com
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