Spark Plug Recommendations

Discussion in 'Maintenance & Upkeep' started by Psyc0, Jun 6, 2010.

  1. Psyc0

    Psyc0 Rockstar 100 Posts

    My 2004 Suburban has only 38,500 original miles, (mostly highway/non-towing, trip miles) however, after owning it for 6 years (since new), I'm beginning to replace items such as hoses, belts, coolant etc.
    Not that the parts are bad, I'm only concerned about eventual part failures due to age.

    I'm thinking the spark plugs installed at the factory were 100,000 miles plugs, but I can't remember if they were platinum or iridium.....Anyone know?

    Also, will the vehicle benefit by replacing the spark plugs with new, high quality AC or Bosch plugs?
    Should I replace the spark plug wires/cables as well?
    Any specific brand/type recommendations?

    As always, Thank You for the excellent responses! :glasses:
    Last edited: Jun 6, 2010
  2. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    You shouldnt have to replace them unless they you have visual confirmation they are fouled (if so you might have other problems), and DO NOT use anything but what is already in them if you do replace them. Changing plugs to a different brand in these Vortec engine just isnt worth it. Just search on this sight and you will see most experiance power and MPG drops going to a "higher quality/performance" plug on a factory ignition
  3. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    What he said. Bosch plugs are a disaster in a Vortec, especially the +4 plugs.

    AC Delco platinums. Gap them at .040" for a small block, .050" for the 496.

    Truthfully, with your mileage, new plugs can go to the bottom of the list. It wouldn't hurt to pull them to check condition, and tighten the gap down if they are at .060". New wires wouldn't hurt though, age seems to be the bigger factor. And once you start moving older wires, like when changing plugs, they tend to start leaking pretty badly.
  4. Chris Miller

    Chris Miller Rockstar 100 Posts

    This particular model comes with AC-Delco Iridium plugs, rated at 100,000 miles. Unless you get a bad valve seal or bad gas, you shouldn't have to worry about them until then. :)
  5. Psyc0

    Psyc0 Rockstar 100 Posts

    Much obliged for the info. :sign0011:
  6. novaman64

    novaman64 Member

    Actual just about to do a 100k service on my 06 5.3 and replace the plugs and wires. I have always had good luck with NGK plugs in my race bikes and in my Nova it was nothing but Champion... Do NGK or Champion plugs work good or should I just go get Delcos?

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    x3 on Going with and Staying with.....A/C Delco Iridium Spark Plugs.
  8. 96_Tahoe

    96_Tahoe New Member

    I put NGK in my vortec after a fresh rebuild, I never thought it ran to it's full potential, and my mileage was complete crap. I never thought that it could be plug related but that seems to be a likely cause.

    NGK run great in small motors....
  9. novaman64

    novaman64 Member

    Well, thanks for the heads up. With the AC Delco's you guys recommend the Iridium or the Platinum? I am hearing conflict on which way to go...
  10. 99'HEARTBEAT

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    The A/C Delco Iridium Plugs are the way go....It's what I went with ......The gap on them is 0.40.

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