Question, progress so far with Pic

[Az]

I'm slowly getting through my list of jobs to try and reduce the sluggish feeling with my car....

I have changed the plugs and have new leads on the way, however when I changed the final 4th plug (one nearest the driver) (so technically plug 4) - I know it's the first plug that ignites anyway. When I removed it, there was some rust type matter around the end of the boot and in the spark plug 'hole'....

Does anyone recognise this? Will my new leads sort this problem out? Is it something more sinister?

Thanks in advance.

[manga_blue]

Water in that spot would have to come from some external source, like washing the engine, driving in floodwater or something like that. Engine coolant would not normally leak into that spot. Don't worry about it, a new set of leads should fix it, wipe out any gunk already in there and in future keep the tops of the plugs dry.