Do the rest of the glow plus still work if one is bad?

[jpatrickc]

I got a p0678 code for #8 glow plug and now the glow plug indicator never goes off when I turn the key on to start the vehicle. Does anyone know it the rest of the glow plugs are still working?
I also have heard that sometimes the tip breaks off in the combustion chamber when replacing the glow plug. What are the chances of this happening? Is it 1% of the time or 20% of the time? I'm considering changing the bad one myself but if there is a high probability of this happening I will probably just take it to the dealer and pay the $100.00 and have them do it under the warranty.

Pat
2006 Chevy 3500 Dually
Completely stock

 

[Ed HD]

If it's still under warranty, just pay the $100 and have them do it. Pretty sure there's a lot that needs to come out to get at the GP's.

 

[CtChevy427]

If you want to do it yourself it's not all that difficult. Here is a DIY on the subject. Good luck which every way you go......

http://www.thetruckstop.us/forum/showthread.php?21280-LBZ-Glow-Plug-Replacement

 

[trotorx2]

I had the same code and took it to the dealer and thinking they would replace just the bad one but they replaced them all for the $100 deductable. About 2 weeks later I get a check in the mail from the dealer for the deductable. They said that GM covered the entire cost.

 

[jpatrickc]

OK. I guess I'll give the dealer a call. I'm still wondering if the rest of the glow plugs are being cycled on since I don't have the indicator to tell me when to start and is it 1 in 100 that break or 1 in 1000.

 

[btfarm]

I gotta tell you that it's pretty rare or we would have been hearing about it all along. There are alot of us here with high miles and no GP issues.

 

[LtEng5]

yes all the other GP's still work.....what happens is that the GPC is waiting for the bad GP to return signal that it is working and leaves itself on until the max time limit is reached..while leaving the rest of the GP's are on during this time they over heat themselves and the tips crack and fall off into the chamber

 

[jpatrickc]

Does anyone have a picture of the head that shows the tip of the glow plug in the combustion chamber that they could post? I'd also like to see a picture of what the end of the plug looks like when it breaks off.

I am trying to see how much of the glow plug sticks into the combustion chamber and figure why there are cases where they break off.

 

[stacks04]

I have never had one break in the cc. They usually break from rust when removing from the cylinder head as it is not a solid piece it is an outer steel shell with the electrode insulated running through the middle. Because of the hollow center the dam things tend to just twist and break off. As far as the tip protrusion into the head I have an lly here next to me and its about 1/4". Never oaid attention but I imagine the other engines are the same.

I would pay the dealer if your still in warranty because if it breaks 9/10 require cylinder head removal and in most that happen here at this dealer cylinder head replacement. If you break it trying to get it out yourself then they may not help you out after the fact.