Spark plug replacement time.... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Steve Tinker · 02-19-2014, 03:36 PM

I can understand mileage affecting plug degredation, but the time limit is not at all clear to me.

What affects the efficiency of a plug made up of metal alloys and ceramics over a 4 year period screwed into an alloy cylinder head, unless electrolytic action between the threads of the plug and cylinder head is a potential probem.

jsceash · 02-19-2014, 03:54 PM

Six plug is less than $50. 1 coil pack $60. No brainer change the plugs.

BYprodriver · 02-20-2014, 08:51 AM

Quote:

Originally Posted by Steve Tinker

I can understand mileage affecting plug degredation, but the time limit is not at all clear to me.

What affects the efficiency of a plug made up of metal alloys and ceramics over a 4 year period screwed into an alloy cylinder head, unless electrolytic action between the threads of the plug and cylinder head is a potential probem.

New electrode has a sharp edge that makes it easier for the spark to jump to ground.
Worn electrode rounds & smooths that edge making a less concentrated arc.

I did read somewhere the time limit was to minimize danger of stripping head threads while removing sparkplugs.