Enjoy the carnage... http://914.ojai.net/SPlug/

-Kevin

wtf happened???

How the heck can that even happen???

"AC/Delco" ...

Any head damage?

JB

Look at pic 29. Looks like that plug hole is toast.

Time to have that welded back up....yikes!

Geoff

Yea, the hole has similar melt damage as the plug. Last night when I first discovered this problem I put in a different plug. The plug threaded in effortlessly. I fired her up, and she ran on all 4, but it didn't sound quite right, almost like a knock, but not... This afternoon I fire her up again, SHWOOSH, SHWOOSH, with 3 cyls firing and the 4th coming & going every few revs... Well, I guess that answered my question about the head. I couldn't see a thing from looking in, so I took about 15 or so pictures of the hole. I got one picture that had enough light and I could see the damage (the picture I uploaded). Looks like I'll have to pull the head (again) and fix/replace it depending on how it looks after CLOSE inspection.

I also took the plug around to a few different shops I know around town today. All but one of the shop owners said "Shit, I've never seen one like that before..." The local VW/import (not rice) shop owner put on his reading glasses, looked it over for a few seconds, and said "Yea, I've seen something like that before." I'll let you guys guess on what could have caused it before I say what John (shop owner) said he thought could have caused this.

FUN, FUN, FUN!

Any one notice these cars lead to ?

-Kevin

Looking at the plug, I'd guess the badness started at the junction between the insulator and threads. Over time, combustion gasses through the body of plug and - ugly.

Close? BTW, what brand plug? I've always been partial to NGKs.

By close inspection, I meant careful inspection. I guess I wasn't really clear. They were Delco's...

-Kevin

OMG! Thats going to leave a mark!

The heads had previously had the threads galled (missing parts of the threads) and that lead to a combustion leak which over time (a few minutes?) burned that hole. If you had caught it while it was running you might have seen the flame jet shooting out.

My local VW expert told me that he has seen a couple plugs that looked just like mine come out of T4's over the years. He said it all starts with a small crack in the head which gasses are forced through. Soon this crack starts to grow and the SP hole and the plug turn into the melted mess I carried into his shop. Nothing I can do about it now though...

-Kevin