| Spark Plug 'Metal Surround' Raised
Has anyone ever come across this before, and more importantly, do you know what has caused it etc...
When I was down at ThinkMINI approx. 1 month ago, Adrian checked my spark plugs for me. When taking out number 4, he noticed that the metal surround in the chamber was raised about 5mm. He's never come across this before, and noticed some oil around the plug as well. He cleared the oil, and gently hammered the metal back down, so it was flush with the top.
Anyway, a month on (considering my car has been in a repair shop for a month, so has probably only had 2 weeks driving in this time), and I noticed the metal has raised up again. Doing the same as Adrian, I gently knocked it back down.
Just checked today (knocked down on Sat), and it seems to still be down, but does anyone know what this is, and what problem I might have?
The BMW repair shop did mention they found yellow sludge in the radiator, so mentioned my head gasket may be on the way out (no sludge on the oil filler cap though). Could this be linked?
I've attached a pic to show the metal I'm talking about - the pic is with the HT lead pulled off the spark plug, but not all the way out.
Help!
Cheers! | 
