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Discussion Starter #1
So, my crew cab dually that I purchased brand new in 05 threw a code that the #2 glow plug was dead so today I went out to replace it. Used penetrating oil as recommended and it came out fairly easily. The new Autolite glow plug however took a bit of persuasion to get in to where the threads would pull it in. After installing it I noticed while trying to get the retainer nut back on the electrical lead that there was a tiny bit of motion and that scared me so I pulled it back out to use another new glow plug only the electrode stuck in the head. Now it looks like the entire top end of the motor is coming off to freshen it with only 147K miles on it. Breaks my heart but I don't know what else I could do. Am I just the lucky one or what?
 

LHN...We ARE the Joneses
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There are extractor tools to deal with a GP.

Your big mistake though, is using a Fjord part on your Dmax.

ONLY install acDelco GPs....as the others won't play nice in your Dmax.
 

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Discussion Starter #3
There are extractor tools to deal with a GP.

Your big mistake though, is using a Fjord part on your Dmax.

ONLY install acDelco GPs....as the others won't play nice in your Dmax.
I suppose we live and learn - the hard way, all too often. We use Autolite plugs in our GM powered drag cars and have had nothing but great luck with them. OK, ACDelco for me!
 

LHN...We ARE the Joneses
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mainly it's a voltage/amp issue that doesn't jive.
 

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Discussion Starter #6
And replace all of them at the same time.
I've already purchased eight new AC Delco 63G Glow Plugs for the top-end rebuild that this truck is headed for. Sadly, this truck has been perfect since new and I really hate to tear it down like I have to to get the rotten stuck electrode out! Well, I'll do the valves all fresh/new and hope it always runs as good as it did yesterday.
 

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And replace all of them at the same time.
My experience is different, Ive replaced only 2 that failed and the rest are doing fine. The GPs are not like spark plugs in a gasser, they work only for a short period of time each cold start.

I would recommend that while you are in there remove all 4 on that side and put some good thread anti seize (I like Kopr-Kote) so the threads will not seize later.

and if you cannot get the GP out even with the extractor you can put a 3.5 ohm on the end of the GP lead and ground it. This will trick the GPCM into thinking the GP is there and working. MUCH less cheaper and quicker than a head removal.
 

Former GM Tech and parts
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If all of the body of the glow plug came out, and its just the tip of the plug left in there, take it out and run it hard for a couple pulls, get the cylinder pressures up a bit and see if it will push it out. When I worked at our local GMC dealer, we had an LBZ that had a tip broken off and lodged in the head. Our service manager at the time said 'lets go out back and force this thing out' and a couple good hard pulls later on the back road, the engine had a huge compression leak-blew the tip out and all was good. Its worth a shot at least
 

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Discussion Starter #9
I've already resolved to do the entire top end. Gasket sets are ordered and new parts, as necessary will be ready for this. Only 147K on this engine but I suspect it would react well to a valve job, new injectors and freshened parts. I love this truck and won't risk this glow plug getting in that combustion chamber where a complete rebuild is required.

I really do appreciate the feedback. I love going to a knowledge center like Duramax Diesel Forum.
 

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I've already resolved to do the entire top end. Gasket sets are ordered and new parts, as necessary will be ready for this. Only 147K on this engine but I suspect it would react well to a valve job, new injectors and freshened parts. I love this truck and won't risk this glow plug getting in that combustion chamber where a complete rebuild is required.

I really do appreciate the feedback. I love going to a knowledge center like Duramax Diesel Forum.
The Army went through a period where they were having glow plugs in 6.2's in HMMWV's and CUCV's would swell up and the tips would break off when they tried to remove the defective glow plug. Different engine but very similar situation, though probably even more subject to damage with the Duramax direct injection vs. the 6.2L precombustion chambers. The word went through the rumor mill that it was okay to drive the broken off piece into the precombustion chamber and install the new glow plug. When those engines came in for rebuild they had all kinds of problems like damaged pistons, scored cylinder wall, bent valves held open by debris from the injector tip and so on. The trick of running the engine to blow out the tip worked a lot of the time though and I never heard of any problems from trying that.

Interesting result of the investigation was that the cause turned out to be cycling the glow plugs and then not starting the engine since the glow plugs rely on fuel being sprayed across them to prevent overheating. I doubt that's the issue here though. I've never cycled my glow plugs without starting the engine and day before yesterday got a CEL that turned out to be the #4 glow plug. My LBZ only has 80K on it so mileage isn't it. Maybe sitting too much lol.
 

"THEEPASUCKS"
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My experience is different, Ive replaced only 2 that failed and the rest are doing fine. The GPs are not like spark plugs in a gasser, they work only for a short period of time each cold start.

I would recommend that while you are in there remove all 4 on that side and put some good thread anti seize (I like Kopr-Kote) so the threads will not seize later.

X2...
 

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Discussion Starter #13
The value of a forum, such as this is the collective mindset. I'm going to warm it up, take it out tomorrow and hammer it for maximum head pressure and see if the expansion of the head, coupled with the extreme pressure might just save me from pulling this top end. Wish me luck. My biggest concern is it getting sucked into the combustion chamber and wreaking havok so I can rebuild the entire mess. 'dunno;
 

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The value of a forum, such as this is the collective mindset. I'm going to warm it up, take it out tomorrow and hammer it for maximum head pressure and see if the expansion of the head, coupled with the extreme pressure might just save me from pulling this top end. Wish me luck. My biggest concern is it getting sucked into the combustion chamber and wreaking havok so I can rebuild the entire mess. 'dunno;
Sounds like a crap shoot.............I wish you all the luck in the world!

Kindly let us know how it works out.>goodLuck
 

LHN...We ARE the Joneses
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and dump the red font.....it's an irritant.
 

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This is where you screwed up. When dealing with the glowplugs.... NEVER force anything.
That and buying the Autolite GPs in the first place.
 

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Discussion Starter #17
Well, the engine started perfectly and ran great but it didn't spit the glow plug out. I suppose it wouldn't hurt to just drive it here in AZ for a bit as we seldom have cold starts like Nebraska and it's been running just fine with the #2 GP throwing me the code and being non-functioning anyway so for now, I'll put the remainder of that broken plug back in to insure the electrode doesn't somehow work itself out when I'm away from tools and leave me stranded. I may invest in that $270. extraction tool they make just for this.

Oh, and about the red font, I've been using that in forums since computers were invented so I'll not change despite the irritant to some. I'll simply apologize and ask you to scroll past my posts. :grin2:
 

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the electrode doesn't somehow work itself out

Isn't that what you want? Wouldn't be hard to carry a glow plug and a wrench with you. Pretty sure they're all easily accessible through the wheel well. I know the entire driver's side is and IIRC the passenger side is just as accessible without the steering column in the way.

Of course, that's without knowing which gen truck you have. I know the LML is very accessible.
 

LHN...We ARE the Joneses
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and ask you to scroll past my posts
....and carefully not hit the delete button. :rofl
 
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