Wednesday, May 05, 2021

65,000 miles on a set of NGK Iridium


  1. They actually don't look too bad to me, but I can see that you might be burning some oil, which is making the gray ash deposits on the ceramic insulator tips. Going from Left to right, #2, 3 and 4 have some oil on the threads, too.

    There could be oil getting past the valve guides or blowby past the piston rings. My car (Chevy Traverse 3.6L DI) was using oil and my GM Mechanic brother told me that the PCV valve can stick open on them. I changed mine and it seems better now. Have you looked online to see if anyone else is having similar loss of oil? I sometimes find good information on owner forums, but there can be bad information, too.

    The gaps look like they haven't changed much from when they were new, so they aren't worn out.

    I hope this helps.

  2. To my luddite eyes those seem massive plug gaps. Do you know what they are/should be?

    1. no, but I can find out with my handy dandy key ring gapper! They look like .050, just a guess

    2. There is a -8 in the part number, which usually stands for 0.8mm, or about .032".

    3. they were exactly 32 thousandths