Forum Discussion

ThomasFour's avatar
ThomasFour
Explorer
Jun 30, 2015

Bad Glow Plug?

My 2008 GMC Sierra 2500HD Duramax check engine light came on during our recent camping trip to Yellowstone. Trouble code reads p0672, which is "Glow Plug 2 Control Circuit." Reported fixes include replacing the glow plug, replacing the glow plug control module, and potentially a fuel injector fix. Anyone encountered this before? O'Reilly auto part clerk was happy to sell me the new glow plug, but I thought I'd do a little more research. Thanks in advance.
Tow Vehicles
  • azrving's avatar
    azrving
    Explorer
    Jun 30, 2015
    Before I would replace anything I would go over all the connectors. Remove and reinstall any connectors so a new bite is established. Remove and reinstall the fuses in the power center.
  • Roger10378's avatar
    Roger10378
    Explorer II
    Jun 30, 2015
    I have had a couple of glow plugs go bad over the years. #2 is the front driver side. You can check the glow plug by checking the ohms across it. It should be under 10 ohms if I remember right.
  • lazydays's avatar
    lazydays
    Explorer
    Jun 30, 2015
    I've changed 3 on mine, one each of the past 3 winters. Each time it cleared the code and it never returned after I cleared it. Glow plugs are cheap and are changed just like a spark plug. Very easy, just don't break it.
  • Itakethe5th2011's avatar
    Itakethe5th2011
    Explorer
    Jun 30, 2015
    My 2008 Silverado thru the same code last week. I bought a AC Delco glow plug from O'reilly's. It took about a half hour to replace. It takes more time to remove driver side inner fender. #2 glow plug is the front one on driver side. Need 8mm to remove nut holding wire on plug and 22mm deep socket (must have, no room for wrench) You Tube has a video.
  • Roger10378's avatar
    Roger10378
    Explorer II
    Jun 30, 2015
    Try 11mm deep socket not 22. Also try to get #12639701. It is supposed to be more robust than the earlier part #. They don't make the earlier one anymore but there might be some in the supply chain.
  • ThomasFour's avatar
    ThomasFour
    Explorer
    Jun 30, 2015
    Thanks all for the detailed responses! I am headed off to get the glow plug, now confident there is a high probability it will solve the issue.
  • Turtle_n_Peeps's avatar
    Turtle_n_Peeps
    Explorer
    Jun 30, 2015
    My LBZ GP went out at about 60K. It was #8. How did I know it was #8? A local mechanic took it out of the OBD port. I thought that was pretty cool that the reader knew which plug it was!
  • Charlie_D_'s avatar
    Charlie_D_
    Explorer
    Jun 30, 2015
    Check your owners manual under emissions. It may be a warranty item. I had a bad glow plug at around 75,000 miles on my 2006 and after arguing with the dealer and GM they finally agreed that it was under the 7 year/100,000 miles emission warranty. Deductible was $100. Second one a month later was replaced at no charge. Third one I changed myself.

    First one went out in Montana and I finished my trip 3,000 miles later and had it done at home.
  • ThomasFour's avatar
    ThomasFour
    Explorer
    Jun 30, 2015
    $17 for the new glow plug at Autozone. Replacement done, but the check engine light is still on after starting it in the garage. Am I out of luck or is the check engine light likely to go off after some driving?
  • Charlie_D_'s avatar
    Charlie_D_
    Explorer
    Jun 30, 2015
    Mine went out after a few starts. I was on the way to Auto Zone to get them to check the codes again when it went out. Thought I was going to have to buy a tester to reset it.

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