Contaminated glow plug?

I replaced the glow plugs on my 2006 t1N over the weekend in order to clear an intermittent glow plug fault coming up on cylinder 1 that had been going off for about 9 months. They all came out just fine but the plug from cylinder 1 was covered with something nasty (as shown in the photo). I repaired black death on that cylinder last winter and this gunk looks very similar to that substance.
I'm not sure how black death could get up the shaft of the glow plug or if this is just carbon built up from a non functioning glow plug causing incomplete combustion on cold mornings?
No codes now and everything seems pretty swell...

Any thoughts?

I can't answer, but I need to replace 2 plugs and I found the wire caps hard to remove and so stopped short before breaking them. How do they actually come off? Squeeze and pull? lol

The plugs should seat down at the bottom so you shouldn't get any stuff up the shaft like that. Did you do anything to refinish the shaft seal when you replaced the plugs? It looks like it was not seated all the way.

Chris

I wasn't aware there was a seal at the bottom of the plug. Does it just consist of the glow plug contacting the aluminum head or is there copper? Can it be resurfaced? Also, are there any implications to having a glow plug not seated all the way besides carbon build up in the shaft?
huh....