Had to replace a Glow Plug so here is some info.
 

Seems I'm seeing a lot of Glow plug failures on LBZ lately, so I though this might help some. The cylinders are numbered front to back like fords odd on the passenger side even on the drivers. I took the fender liner out to get to them. Others might have to lose the tire too, but I'm small. You can do some of them from underneath aswell. You need to be genital GPs ain't as strong as they look and this area can be heavy corroded for ya'll in the rust belt. Need a 8mm to remove the bolt that holds on the ring terminal. Need to check the resistance from the GP terminal to the block if its over 1 ohm its bad. Its a 12mm wrench or Med/deep well socket. Deep wells won't fit around the steering shaft on #4. I put a little anti seize on the GP just to make sure it doesn't get stuck after I replaced it. Get them good and sung IIRC the TQ was 13lb ft.


GM Part #97364968 for the Glow Plug its a 61G and was $28 at the dealer.

If its not the GP check the ohms of the harness and that its not grounding out. The control module is at the back drivers on the engine. The plug releases by pulling a tab under where the wires are. Pull tab away from the plug while wiggling the plug. I never could get the GPCM to energize the GPs with EFI, so to check that you are getting power you may need a tech2. Even though the the GP light stays on when you have a CEL I don't think they are getting power. So you don't have to worry about burning them up before you get them fixed.

The GPCM is Part #98041624 IIRC ~$120

For some reason the manual says to replace all 8 GPs if the GP is over 1 ohm. Rttoys and I where thinking this is a typo it doesn't make sense.

thanks for the information.

My thoughts on the if one is bad replace them all is this, they have been cycled all exactly the same ammount of times. if one goes bad today and you replace it, then another goes bad a week from now, then 4 months later 3 go bad, by the time you replace them all you forget which ones were replaced when, so they all have a different lifespan when thinking they all should go bad at about the same time.

if you have a gas truck and one spark plug is bad do you replace the bad one or all eight?

True, but I don't replace good parts. Now if I start seeing what your saying I might do all 8. I keep a log of everything I do to my truck.

Parts houses tell you to replace everything in pairs or replace all or nothing. It's their job and that's how they make money.

There is also a big difference in replacing 8 glow plugs @ $28 each (that are not considered a wearable part) and replacing 8 spark plugs @ less than $10 each (that is a wearable part).

good point, never thought of it in that fashion, i've replaced Powerstroke glowplugs all at one time.... i'd rather do it once and wait a few years to do it again then to do it today, do it 2 months from now again, 3 times the next year.... you see the pattern....

duramax plugs are very easy to get to, they are in plain view once the plastic fender liner is removed

i c, on the 7.3 powerstorke it is under the valve covers..... PITA

i hear number 7 is a real pita to get to

no not really, perty easy if i say so....

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