I know you guys are probably tired of seeing me post pictures here of the same old subject, but I just got this digital camera and am learning to take and post pics. plus it is an interesting view that a lot of folks might otherwise not get to see.

Here is a pic of the right hand cyl head (pass side) with a close view of #4 combustion chamber (look closely and see no threads on plug hole). also you can see the coil that looks pretty rough after the spark plug blew it to bits. also, that is the spark plug (stuck in one of the coolant passages) with lots of aluminum on the threads and a damaged electrode. the plug was found lying in the service lane, I think that is how is got damaged, not from any piston/electrode contact.

later,
chris

 

'fords,

keep posting them. Not often we get to see preserved images of a complete teardown.

 

No, we are not getting tired of you posting these pics! You are performing a great service--please continue. We are seeing things I hope none of us end up 'having' to see but your pics are almost priceless.

Thanks again,

Dan

 

Keep them Coming and Thank You!

 

I just got my truck back from having this same repair done 2 weeks ago, and my plug looked just like that (with the aluminum on the threads and the electrode crushed down), but unlike the truck you're working on there, my blown plug never left the engine bay, so I don't think it was from hitting the ground (or service lane as you said).

My best guess as to what happened (even in your case) is that when the plug blew out, it didn't initially totally leave the cylinder and engine bay...it bounced up and down a few (hundred) times on the threads of the cylinder head and little by little shaved off bits of aluminum (that you see on the spark plug threads), and at some point the electrode came in direct downward contact with something else, which forced it to "melt" onto the other electrode (are they both called electrodes?). Regardless, whatever happened is all bad.

BTW, Thanks for posting the pics, we all truly do appreciate it.

Later...

GK

 

Mine was smashed like that also. I believe it was caused by the plug boincing up and down in the head and beating on the aluminum. When it finally got to the dealership for repair the entire tip was gone...