glow plug drilling/extraction

[IDI_Journeyman]

I will include a picture below, I have this 7.3 idit on a engine stand in my garage and glow plug number 8 has broken the top off of it. Iv been soaking it in panther **** for the last couple days and would like some advice before I go drilling.

My current plan is to let it soak, clean the area and drill a small pilot hole. drill a larger hole for my extractor bit, then before I use the extractor I apply heat all around the glow plug itself to loosen everything up and expand the metal.

Iv gotten broken bolts out of engines before, but this is the first time Iv had to mess with a glow plug. Any advice is appreciated as always.

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[Thewespaul]

Thats a sound plan, worst case scenario you can remove the precup and work it from the opposite end. Plenty of 7.3 heads ruined by these glowplugs, so take your time and use lots of lubricant.

 

[DrCharles]

I'm assuming the head is on the engine and you'd like it to remain there?
If so, please be very careful with extractors, especially the "Easy Out" (two lies in one).

Can you weld a nut to the stub of the glow plug, then just turn it out?

so take your time and use lots of lubricant.

TWSS

 

[IDI_Journeyman]

Yes the engine is still together, I’d prefer not to take the heads off. But if it comes to that I will. I’m liking the bolt head idea Dr.Charles, can you mig weld on a glowplug?

 

[Oledirtypearl86]

Like drcharles said you can weld a nut on the top of the stub when I do that trick at work on broken bolts I weld a washer on first then the nut also I've had luck with left-hand thread bolts for some of the smaller things I'll drill the holes tap them really quick and thread the bolt in

 

[Frstdiesel]

I always weld a flat washer to the bolt /stud that is the correct size and fits the broken stud/bolt closely.
Then I weld a nut to the washer.
Let it cool a bit, then with an impact feather the trigger to break the rust bond.
I did this on my turbo housing when all but one of the stainless 5/16" bolts twisted off. Worked like a charm.

 

[Thewespaul]

I think the glow plug may be stainless, so its possible to weld, but a regular flux core may not make a good enough weld. If you are setup for welding stainless, go for it. Id definitly go with the extractor first then try go to welding.

 

[ttman4]

Several yr ago I got some cheap sets of Chinese GP off EBay. Swelled, broke off, & all kind of nasty stuff. 4 of them broke off too low to weld anything to them. I wound up VERY CAREFULLY drilling thru with a small hi-quality bit, turn engine over few times to blow stuff out, then drill thru again with next bigger size bit. Turn engine over each time to blow shavings out. Finally got each GP out.

My engine was still in truck. Luckly I didn't break a bit off or suck shavings the wrong way, at least none I know of.

Pucker factor was very hi & intense during the job!!!

 

[jaluhn83]

I'd leave it alone. Having 7 of 8 plug woln't make too huge of a difference in starting, and trying to get that stub out now has a pretty high chance of turning into a head job and possibly a junk head.

 

[subway]

i have had luck slowly drilling out broken off spark plugs by taking it slow and loading up the bits with grease. the shavings slick to the grease if you keep pulling it and refreshing it. you can even help by pulling the injector and running shop air into the injector hole to blow chips out the glow plug. just make sure to wear some safety squints.

i would try welding first but if that does not work i would drill.

you will have to look up the timing marks but you can try to make sure the piston is locked at TDC so even if you do drop a piece of the tip down the bore you can blow it out the injector hole. with the piston at TDC it should prevent any pieces from dropping into the cylinder keeping them in the pre cup area.

 

[catbird7]

Definitely weld first! Find a nut that just fits over the glow plug stump, then weld inside where the threads are. Have your wrench / socket ready and try to back it out immediately when you stop welding. Heat from welding will help break it loose. Sometimes an impact gun with a light clutch setting will also help break things loose. Good Luck!

 

[jaluhn83]

I suspect that the actual heating element isn't going to drill worth a darn - I'd expect it to either fracture and come out in chunks or just be impossible to drill.

Keep in mind too that as soon as you start drilling/moneying with it you have a good chance of getting it torn up enough to no longer seal, but also not be able to plug it back up.

 

[YJMike92]

I'm thinking the weld first idea may not be the best. Drilling through heat tempered and deformed metal will get a little interesting. It is a very good option but once you start welding it may be your only option. Just my two cents worth.

 

[Oledirtypearl86]

Has anyone ever used one of them fancy extractor kits? They seem to work well in the videos iv seen

 

[DrCharles]

Which ones? As I originally said, stay FAR away from "Easy-Outs". There is one where you drill a hole, then hammer a splined extractor into the hole. I've found that for really stuck bolts, it either spins in the hole, or twists to the point where I was afraid of breaking it off just like the Easy-Out. I think the problem is that the splines expand the bolt against the hole, making it even tighter.

Welding usually works the best... but as YJMike pointed out, you are then committed to that approach.