Review on ACDelco 9G Professional Glow Plug by James Jenkins

OEM part, easy to install with standard tools and minimal wrench. The only difficulty was unscrewing the plastic fasteners of the wheel arch liners. They seem ridiculously stubborn when removed, but luckily they're easy to install. OBTW. With the wheel and tire removed, you do not need to completely remove the liner. Start removing the fasteners from the front, roll back and to the side, leaving the last pair of fasteners in place. Much easier than rotating the entire liner into position to reattach. OBTW-2. My Duramax cylinders are numbered front to back, 2-4-6-8 on the driver's side and 1-3-5-7 on the passenger's side. Reading the codes will tell you which glow plugs have failed. It's simple enough that I only replace them in the event of a breakdown, which started after about 175,000 miles / 8 years of service. No big deal as long as 3.