Hello , I am new to the forum and to the Duramax Diesels, I bought a 05 GMC 3500 4x4 4dr Dually from a auction, long story short I snaped no# 8 cly Glow plug trying to remove it , Question can I still use the truck until I get the time to get it out ? the head broke off flush with head and the long skinny rod came out with nut part, I know it will start with out it but will is cause any damage other then the check engine light being on.. Thanks Ken
Help: broken glow plug
- Thread starter allwheeldrive
- Start date
If the whole rod came out you are SOL. Also we usually have to remove the head to get the rest of the glow plug out.
You could drill the outter sleeve out. infact, MOST of the time, not all, you can use reverse drill bits and they will usually grab it and back the sleeve out. You can also thread another smaller bolt into it to keep the compression in.
NO.7 black oxide 135 split point drill bit
1/4 20 spiral flute bottoming tap
Left handed 11/32 maintenance length drill bit
1/4 20 spiral flute bottoming tap
Left handed 11/32 maintenance length drill bit
Thanks for the Quick replies I appreciate it , so the skinny rod is not in the tube of the glow plug? so its a open hole now? that sucks, @custom8726 may I ask what I do with that hardware?
The above list is the drill bits and taps you would need to drill them out.
It's a PITA FYI but saves pulling the heads and works well if you are careful.
The small bit you will use to drill into the body of the glow plug, Then you will use the 1/4" tap.
Next use the 11/32 (Large bit) to drill out the area of the glow plug that is stuck into the head. (You can measure this area/depth on a old glow plug and wrap tape around the 11/32 bit so you know when to stop drilling) Be carful to drill dead center and at the right angle to avoid damaging the threads in the head. There is only approximately 1/16th or less margin of error before damage will occur to the threads.
If all goes well the left handed 11/32 will spin the remaining stuck glow plug threads out as well as the remaining glow plug tip.
(The body of the glow plug catches all of the shavings at this point as well so there are no chance of getting metal shavings in the engine)
If the remaining glow plug does not come out with the left handed drill bit
you can use a bolt to thread into the glow plug body that you previously tapped in the second step. By threading the bolt in you can usually put enough forward pressure on the remaining glow plug to break it loose and it will then in turn come out when you reverse the bolt.
If the threads are (Mildly) damaged you will need a 10m X 1.25 tap to fix them.
Just remember there is nothing there to catch metal shavings from going into the head at this point so I would suggest using some grease on the tap to catch any small shavings caused by cleaning up the threads..
Good luck :thumb:
Be careful chasing the threads with the tap, dont go crazy with it or the glow plug will be loose in the head. My buddy did this and then i had to put a time-sert in it for him.
Thanks guys for the great info!!, I ordered the 11/32 LH drill bit today, have no idea if I can get the drill in there being its number 8cly and firewall is right there , but I will try. Question in the mean time could I drill and tap a hole in a pipe cap and thread the new glow plug in it then thread the cap onto a piece of pipe to shield the glow plug heat, then ground it and put the wire back on to get the check engine light off so I can get it inspected? should work temporarily I would think?
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Harbor freight sells a cheap right angle drill that may come in handy..
In N.Y. a glow plug or check engine light will not fail a inspection on 3/4 and 1 ton trucks, Is maine different?
@custom8726 Thanks for info, I do have a right angle drill I need to wait for drill bit to see, but lets hope the truck gods are with me! yes in Maine any check engine light is a fail
Just a update, success glow plug removed and new one in Thanks for all the help, now onto the rusty brake lines and ABS bleeding problems lol
