First post so please bear with me.

Well I just "did" the glow plugs on my recently acquired 99 7.3 and while 7 came out with no problem, one of them gave me more resistance when turning than expected and then "snap". Now here is the interesting part. What actually came out is the threaded top portion of the outer wall, while the rest of the outer wall and the electrode are still in the block. I have done a lot of searching and it seems that usually the electrode detaches from the outer casing and the entire outer casing comes out with only the electrode or part of the electrode stuck in the shaft (usually due to carbon buildup or swollen tip). In this case though, the outer wall of the plug sheared in two, which seems to imply that the outer wall itself is what is stuck in the shaft and not the electrode. The attached picture hopefully explains what I am trying to say.

I can easily latch on to the end of the electrode with some vice grips, but even if I managed to get that out, I would still have the outer wall of the plug in the hole. At the moment I just screwed the threaded part back in to keep the everything from blowing out so I could crank the truck. It cranked right up and seems to run fine. My inclination is to just leave it as is and hope that 7 good glow plugs will do the job, as I have some nightmares about making things worse in trying to make them better. Does anyone have any opinion if this is a terrible idea? Any chance of the electrode falling into the cylinder if this much of the outer case is still there? Anyone with experience on this kind of breakage? Any ideas on removal methods? Again, I have seen a lot of advice on how to remove stuck electrodes, etc. but none on a stuck outer casing.

Any help is much appreciated!

 

Well, I would never run it with a glow plug "hanging" in the hole only held in by carbon build up. When it drops, you are going to be very, very down in the dumps for the cost of that repair. You might try a drill bit and and easy out type tool, but if that does not work the head might need to come off to retrieve the rest of that glow plug. Certainly not the end of the world, but worth not destroying the head and piston when the glow plug lets loose from the walls of the hole it is carbon-glued to.

 

It's easier just to remove the head, what side was it?

 

Yeah, this sounds really bad. Does anyone know how successful he'd be trying to remove the electrode part separately from the outer shell? I'd be afraid of the business end of it breaking off and falling in. But if he could get the entire electrode out first, then the screw extractor idea Mike mentioned might work for you. But whatever you get out, make certain you're not missing any pieces.

 

If it were me I would start looking at the best method of removing the head. Be it with engine in truck, out of truck, whatever.

I believe the heads are really quite heavy too, so there is that to consider.

I am sure a lot of these guys have done this many times before and give you some step by step instructions.

 

I concur.. Remove the head.

 

Damn...knew it was going to go the "remove the head route". Anyone have any idea what would cause the outer casing to get stuck? I understand why the electrodes do, but the casing is a bit of a mystery. The rest of the plugs I pulled were the standard Motorcraft ZD11's, so I don't suspect there is any reason to think the last one would be different. Anyone heard of a ZD11 dong anything of this sort?

 

It probably was one of the Autolite ones that the PO installed and couldn't remove it as well? It's not that hard to remove the head the problem is that it's a heavy sucker, but with an engine hoist it can be done solo.

 

Okay, so if the likely solution is to remove the head anyway (and this may completely evidence my lack of knowledge here), is there any harm in trying to get the plug out with the head on since if something does break and fall in, it should be easy to retrieve once the head is off anyway?

 

That would be my thinking as well. But as I said before, keep every piece you get out and put the glowplug back together like a jigsaw puzzle when you're done. If you think you're missing any pieces, then the head's coming off. But even a little tiny piece or shard could wind up on a valve seat or ring land, and then the rebuild costs go even higher.