Not on a cummins, but on an older mitsubishi diesel truck. I tried to remove the glow plugs, but could only get one out. The other three would unscrew, but i couldn't get them to come out.
I tried pulling on them with pliers and nothing.
Any ideas of what might be causing it?
Thanks

 

Would they unscrew but you just could not pull them out of the engine or would they not unscrew.

The glow plugs on my 6.2 would sometimes not pull out because they got a buildup of carbon towards the ends of them and would not pass through the hole.
I was able to hold them with vice grips and work them loose by pulling them back and forth scraping them clean (a shot of WD-40 also helped, just a shot so there is not enough to fuel the engine on startup) then they would pull out but be careful you don't break the tips off in the head, then you must remove the head to get the pieces out.

 

If the glowplug relay went bad and the glowplugs got stuck on, then it sounds to me like the ends have mushroomed and your going to need to remove the head. I've seen this happen on a vw diesel.

 

If it's a matter of not being able to unscrew them squirt some PB Blaster around the threads and let it sit overnight. They should back right out in the morning.

 

We had that happen in the Marines quite often on the hummers. Couple guys wrenched on them pretty hard and broke them off in the cylinder. Ours was not because of a bad relay, it was from the operators thinking if a little is good, longer must be better when they held the switch manually. We did'nt even call them operators.....they were known as aimers!!

 

They'll unscrew, but not come out.

Don't know much about the truck, i just got it and it won't start. I think the last guy said he hooked up the glow plugs to a battrey direct. Also, the water temperature gauge wires look to be chewin through by mice, so that would probably mean the glow plug control never shut them off. Not to mention end less cranking and cycling the plugs by other people trying to get it started.
So i'm sure if one of these things didn't screw something up, the other probably did. At this point i'm leaning towards the end being swollen up. Is there any way to get these things out without yanking the head? I was reading about some guy drilling out the main shaft and being able to remove them in his engine.
The plugs are all iron based so i can use a magnet to pick up extra crap that falls off, so i was thinking maybe remove the injector and swab out the cyclinders.
Any ideas?
Thanks

 

IMHO I think it would be better to pull the head and and move it to a workbench, rather than risk pieces in the cylinders. This would also benefit you in other ways too. You would be able to set the valve lash to the proper settings, inspect the engine internals, clean the ports if nessessary.

 

Go quick and dirty and see what happens. You should be able to tell if you get all the peices out. I'm assuming you got the truck for great deal or you wouldn't be in this position. So you have some margin to work with. I'm pretty sure the injector holes are bigger than the glowplug holes so that is the way to go. Fords have the same problem from time to time, so check out some threads on the ford sites for ingenious ways to take care of the problem. The glow plugs do not mushroom usually, they just droop from getting too hot. I think your on the right track though. If you really don't give a **** screw the plugs back in and set up a cold start either injection system. If you don't have glow plugs to set the starting fluid off early problems are minimum just make sure you give it small squirts. Removing the heads is for gomers! .....check valve lash and make sure the ports are clean!?? Please, I'm sure the guy has more important things to do.

 

**** screw the plugs back in and set up a cold start either injection system

I don't want them welded in place. Come to think about it, the glow plugs are about the same thing ford uses on the power joke/stroke.
Man, all this makes me happy to own a cummins with no glow plugs!

 

I suspect that they are swelled up on the end. You might try a vise-grip with a slide hammer adapter. The size adjusting screw on the vise-grip is replaced with a special one that can have a slide hammer threaded onto it. I have one in my tool box.

 

They will not weld them selves into place. I'm not talking high voltage, only a bit of starting fluid. It probably has warnings all over not to use it but that is because it has glow plugs. If the glow plugs don't work you don't have much to worry about when using starting fluid.

 

It is easier on the engine to use WD-40 for starting fluid than ether.

I plumbed in a WD-40 injector on my 6.2 because every time I would switch tanks I would run out of fuel and this made priming a snap, pull a cable from inside the cab and start the engine.

Are the glow plugs directly in the cylinder or in a pre-chamber?

 

I'm with Jim on this one. Use WD-40. Don't use starting fluid (ether) then your going to risk damaging the head.