Glow Plug issue

[Willcoc]

Have check engine light on so went to Advance to have the code read. #2 glow plug (did not catch the actual code number). Have not dug into it as it is cold outside to really work in it. What should I look for and should I replace all the plugs instead of just one? Thoughts?

[rapidoxidationman]

If you're familiar with the use of a multimeter, you can easily check the glow plug for continuity (something just north of zero ohms). If the plug shows an open circuit or very high resistance between the hot lead and ground, the plug is fried. A bit of antisieze on the threads of the new one will make it easier to disassemble down the road.

[gary_lucas]

I've got the same thing, but on #6 (P0676)

Once the weather warms up I'll replace it. Right now it's too crappy out and I don't think having one glow plug ineffective is going to hurt anything. Especially given how the truck's not moving much ATM.

To the best of my knowledge there's no value in replacing glow plugs other than the one that's experiencing an issue.

[rapidoxidationman]

When you do get around to replacing the bad plug, don't get aftermarket. They heat slowly and don't work well at all, in my experience. I changed all of mine out when I had the engine torn apart to replace head gaskets 100K ago. With the new ones in, the truck would take several seconds longer to start. Put the OEM ones back in, and the problem went away. Just my $0.02

[gary_lucas]

When you do get around to replacing the bad plug, don't get aftermarket. They heat slowly and don't work well at all, in my experience. I changed all of mine out when I had the engine torn apart to replace head gaskets 100K ago. With the new ones in, the truck would take several seconds longer to start. Put the OEM ones back in, and the problem went away. Just my $0.02

Good to know, my local parts place tends to steer everyone away from aftermarket for everything.

[Kennedy]

In my experience with the late model trucks (LBZ, LMM, LML) if one goes do the entire bank and be ready to do the other shortly.

We have the Delco plugs available but you'll want to contact me direct.

[gary_lucas]

In my experience with the late model trucks (LBZ, LMM, LML) if one goes do the entire bank and be ready to do the other shortly.

We have the Delco plugs available but you'll want to contact me direct.

Is that just a wear and tear thing? IE their all about the same age and wear so expect to see them all start dying shortly?

I've got one that likely needs a replace. I'll check the connector shortly. Does that apply for LLY's as well?

[rapidoxidationman]

Given the PITA of pulling out the wheel well to do the job, it's worth doing the whole side in my opinion. Wallet permitting, of course.

[Kennedy]

Is that just a wear and tear thing? IE their all about the same age and wear so expect to see them all start dying shortly?

I've got one that likely needs a replace. I'll check the connector shortly. Does that apply for LLY's as well?

The LLY uses a different plug. They seem to be pretty darn reliable. Curious what was done to yours when the head gasket job was done? We typically replace them right away due to ease of access and starting fresh. Also, quite often the terminals twist off so we have no choice.


The LBZ thru LML use the same plug. Glow plug life has not been a strong suit of these models in fact GM had a special policy bulletin extending warranty to 10yrs/120k for certain LML's.

I have 70k on my 2012. Recently got a code for plug #1 bad so I replaced it. I also R&R'd 3,5,7 and lubed the threads proactively. I put it back together and checked before replacing the wheel liner and now I have #5 and #6 showing bad so I went thru and replaced all of them.

The LBZ+ plug part number was superseded to what may well be a more durable plug.

[rapidoxidationman]

FWIW, 240K miles on my '05 and as far as I know they're the original glows.

[gary_lucas]

The LLY uses a different plug. They seem to be pretty darn reliable. Curious what was done to yours when the head gasket job was done?



IIRC when we did the final review of all the work they said: "Oh hey, one of your injectors looks very slightly sketchy and one of your glow plugs looks like it might be done."

We decided that was work I could do on my own if I had issues down the road.
Also, the glow plug control module was toast and I just replaced that which is why I'm now seeing the error.

I'll just replace it and hope for the best. I'm not seeing anything weird WRT to the injector so I'm not worried about it for the time being.

My truck is just cresting 240k and I'm hoping to see it to 500k :D

[More Power]

Might not be a bad idea to ohm/continuity check the suspected bad plug to verify before doing much of anything. There have been instances of a bad wire or even a glow plug controller causing glow system codes. If that's the case, knowing now will give you time to consider the path forward before spending money. Jim