Hope all is well with you and yours!
Just wanted to let you know that I had the truck in the shop again for a check engine light. Glow plug....again... 4th one in two years. BUT, they found a service bulletin that allows them to change them all and not wait for a failure! So they changed all 8 even though some had already been done!
On my third GM service dept. due to trust issues with the first two...seems I may have a winner in this one!
You might want to ask about it next time you have yours in for service, might save on some aggravation!

Take care!