Glow Plugs

Turtle n Peeps wrote:
Sorry but a burnt out glow plug does not swell like has been reported by a few on here. It doesn't do anything but not heat the cylinder and aid in cold weather starting.

Why glow plugs swell.

I find it amusing that dealers suggest replacing all the plugs when GM DOES not. I had a CEL light come on while towing and in Montana. Dealer said it was glow plug. I responded that it was emission related and I could continue until I got home. He agreed and cleared the code bit it came back on in a thousand miles or so.
Got back home, checked the owners manual and under the emission warranty it was still covered but a $100.00 deductible. Dealer wanted several hundred dollars for 1 plug. I called GM and they also said it was not covered. Finally convinced him that it was. Paid the $100.. A second plug failed later and I then found a TSB giving instructions on replacing ALL after doing a OHM check but I don't remember what the trigger point for doing so. Dealer had issues with that. Paid my $100. deductible and had it replaced. Later had a $100 check from the dealer stating the second plug was replaced as a "good will" gesture.
After my third failure I bought an OEM glow plug for about $20. and replaced myself. Takes a small deep well socket and small combination wrench of which size I do not remember. Disconnected the wires and carefully tried to remove. Turned surprising easy. Put a little never seize on the threads and put the new one in. 30,000 to 40,000 miles later I traded for a new truck and never had another issue.
If I were you I would carefully see if the plug will turn and if so do myself. If it does not break loose then I would have the dealer do it. If you decide to replace them all I would change the ones I could and have the dealer do the rest.
Changing them all will not be cheap. Dealer will probably mark them up to $60-$70 or so and labor would be at least $100. per hour. IIRC, dealer tried to bill me for over $200 for one. Replacing all may run closer to $1000.