<E36> M3 Piston slap

[mng2@xxxxxxx]

While investigating a 'ticking' noise and experiencing engine 'bogging', I
removed the stock Bosch sparkplugs to find the ground electrodes bent
inwards(1 plug).  The center electrode seems to be pushed in a little also.
Anyone have any ideas what would cause the piston to hit the plug?  Could
it be the vavles hitting it?  Just wondering as I schedule an appointment
with the dealer.  I did put in a bottle of Techron Fuel Injection cleaner.
I always run premium unleaded.  Any ideas would be appreciated.

Thanks
Mike Ng
97 M3/4

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