Well I searched the forums for a solution to this one and couldn't find one, yestereday when I was taking my glow plugs out to do a compression check. I found that one of them has the place where you put the socket to wrench it out, I guess the head, is spinning, could the plug be fused? Is there a simple way to get it out? Do I have to get it out? Would it keep the engine from starting?
Thanks

The engine will still start on the other 7 glow plugs. I had the same problem on mine but I was pulling the heads off so it made it a lot easier to do on the bench. What I did was break the top off and drill the center of the plug, then I used a E-Z out and got lucky. I don't know if it will work for you but it did for me, other people probably have better ideas.

Thanks, the plug has good voltage, should I not worry about it? It was only because I wanted it out with the rest to do the compression check.

If the glowplug is still good then it's not likely swelled where you can't remove it. Glow plugs are usually a pain in the butt to remove when they've in there awhile. I usually just unscrew them until they don't come out any further, then grab the base and rock it side to side all the way around. Then shove it in and then pull it back out, I do this until it's out. You can also get your socket on the glowplug and unscrew it while you keep your fingers on the threads of the plug and keep a bind on it towards coming out.

Good luck!

The glow plug is probably already unscrewed and carbon around the tip is holding it in place. Have a helper crank the engine while you hang on to the glow plug with some vice grips, the compression should help you get it out. If it doesn't come out on the first try, try holding the glow plug in against the force of the compression while cranking and it will act like an air hammer to remove it.;)

Be sure to wear safety glasses when you try the blow out as that will generate almost 300 PSI!!! I hope the glow plug head is not mushroomed as that can mean removing the engine head. I always use anti-sieze compound on mine when I install them. I have never had a problem in removing mine. We always used anti-sieze on the sparkplugs for aircraft engines from V-1650's to R-4360's.

Ok I will try those things and let you know what happens. Can one bad glow plug keep the engine from starting, if it's the type that requires the relay light to go off before starting?
Thanks