Plugs & Wires

Discussion in 'Maintenance & Upkeep' started by duckduckdog, Mar 14, 2013.

  1. duckduckdog

    duckduckdog New Member

    When do you typically change them.... I believe the manual calls for them at 100,000, but I'm wondering what you guys are typically doing.
  2. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member

    When my Truck was New, I removed/replaced the old ones, which had.....85,000 miles on them, when looking at the old ones, they looked Great!!, but I went ahead and installed new plugs and wires......as to when is a good time to replace the plugs-wires.....:neutral:.....IMO depends on how many miles you have on them and also How your Truck is Running????

    Edit:.....I would also mention, that I just installed, a new set of Plugs-n-Wires, my truck has right at 170,000, and once again they(Old Plugs)Looked Great....both sets of old plugs, could have gone to 100,000 miles with no problem.
    Last edited: Dec 9, 2013
  3. Pikey

    Pikey Moderator Staff Member

    I agree with @99'HEARTBEAT, I replaced the plugs in my 2002 with 80,000 miles and they looked fine. The gap was still within spec. I also replaced them in my 2003 yukon xl with 120,000 on it when I bought it and they still looked pretty good and were still within spec. I don't mind replacing them every 75,000, they are not all the expensive and it gives me a change to get the old plugs out and anti-seize the new plugs. One of my Mechanical Engineering professors worked for Ac Sparkplug, he was the lead engineer on the platinum and iridium plug development projects. He said that when they were developing them, they considered them to be a "lifetime" plug. They were more concerned about the plug seizing to the head passed 100,000 miles than the plug failing at that mileage. He said that most of the tests they ran the plugs outlasted the engine itself. It was decided that if the plugs were to start having issues at high mileage (over 300,000) the consumer would not be very happy about the cost of complete head replacement because the plugs were stuck.
  4. duckduckdog

    duckduckdog New Member

    Truck is still running great, just didn't want to wait too long and have them siezed up. Had that happen in a '94 S-10 and it was a bear!
  5. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member

    Last edited: Dec 9, 2013
  6. TRPLXL2

    TRPLXL2 New Member

    My 01 s10 4.3 got a tune up at 56,000, rough idle and would stall a lot. 3 out of 6 were fouled, ac delco plugs are awesome, but they don't recover once they are fouled.

    i pull the plugs out right when the vehicle is brand new now, I smear the threads down with never seize made for aluminum heads and reinstall them. I could tell you some good stories about aluminum heads lol!!
  7. Goldie

    Goldie New Member

    Hey TRPLXL2
    What kind of plugs did you re-install on your S10?
  8. TRPLXL2

    TRPLXL2 New Member

    I went with the ac delco iridium platinum tips, I was told the vortec motors are picky about plugs so I went with what was suggested. I mentioned the fouling because on my ls1 swap we just finished, we fouled out close to a full set while getting it tuned. They do not clear up on there own, this was how I learned how to tune ha ha. Lots of p300 codes.
  9. Conlan Rose

    Conlan Rose Super Moderator

    Yah... Change them before they seize or you will have this happen....
    2012-11-22_09-41-38_294.jpg 2012-11-22_09-11-52_118.jpg

    Oh the memories....... But the plugs I (my shop at that point) removed minus that one were in great shape. Use lots of PB blaster or other penetration oil and make sure you add the anti-seize. I may just pull and put back in my plugs every 30,000 to keep them from seizing.
  10. TRPLXL2

    TRPLXL2 New Member

    Yep conlan rose is right, when we had the ls1 on the engine stand we changed the plugs and two of them snapped off in this manner. The one destroyed the threads in the head, ended up have to use a keen cert to fix the threads.

    a friend of my dads has and still is working for a Chevy dealer since the 70's. he said very rarely do people actually get 100,000 miles on these plugs. Your engine would have to be running perfect all the time, and I know myself sometimes you can't afford to fix something right away so you drive with the check engine light on for a couple months, well that's why they go bad early.
  11. Pikey

    Pikey Moderator Staff Member

    I would only put the factory recommended ac plugs in it. After speaking with my professor and a few GM techs they said that they usually only see coil pack issues when there are not stock plugs in it. I know that it has been debated here before, so no jumping down my throat folks. They all said that the system was designed for the resistance that the AC plugs provide. Although aftermarket companies may make plugs made out of the same materials, they are made for a wide range of vehicles not just GM, so their resistance may not be within the spec that the system was designed for.
  12. duckduckdog

    duckduckdog New Member

    Thank for all the info - and the link to the plugs. I just turned 70,000 but was thinking about going ahead and doing this at 75,000. Think I will probably go ahead and make it happen then. Any tips on changing these? Any ones that are hard to get to?
  13. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member

    One last item I would mention, and that is when you do install New A/C Delco Plugs(Iridium) they are Already Gaped right out of the Box, Check the Gap, to be sure its set at.....0.40, if the Gap is off.....Do Not Attempt to Re-Gap them, as the Iridium Tip can be Easily Damaged,

    ****Below is a part of a G.M Service Bulletin, regarding the Gaping of the Plugs(Iridium Tip),

    • A New Spark plug has been released for use in the above vehicles. The New Spark Plug has an Iridium Tip instead of the current Platinum tip. Due to the different Tip design, the gap of the spark plug has also changed.

    • The New Spark Plug, P/N 12571164 with AC Delco P/N 41-110, is gapped to 1.01 mm (0.040 in) when the spark plug is made.


    Notice: The Spark plug Gap is set during Manufacturing and should not be changed or damage to the Spark Plug may result. Any New Spark Plug found to Not be properly gapped should not be used.
    Last edited: Mar 15, 2013
  14. duckduckdog

    duckduckdog New Member

    great information - thanks a lot!!!
  15. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member

    One last Item......The Spark Plug Fastener Tightening Spec's. are 11 lb ft and also make sure to use some.....Anti-Seize Compound on your Spark Plugs, is particularly advisable with Engine Head's made of Aluminum. and use Dielectric Grease, Use your finger to spread the Dielectric Grease around the Ceramic Portion of the Spark Plug. This will help maintain a dry environment for the Spark Plug to Wire connection. The Grease will also make Re-Installation of the Plug Wires easier.



    Last edited: Jun 10, 2013
  16. marksoldtowne

    marksoldtowne New Member

    A careful inspection of your plug wires can avoid any problems.An arcing plug wire can cause a weak spark or no spark at all in the cylinder with the bad wire. This makes your car run rough and can affect your gas mileage. It can also cause unburned fuel to pass into the exhaust system where it can harm your catalytic convertor.so best time to check plug wire while you change your spark plug.if you don't ccheck it properly then you will get heavy loss.
  17. McClintoc

    McClintoc Super Moderator

    I've replaced my plugs twice now - every 75,000 miles. I replaced the wires both times as well. Make sure you get your gap size from a reputable source, and by that I mean, the owners manual or possibly a sticker under your hood. The last time I purchased plugs, the store printed my gap size on the receipt and it was not the correct size.
  18. K15 Blazer Guy

    K15 Blazer Guy New Member

    chevys love NGK plugs, and if you can, upgrade the ignition coil as powerful as you can.
    I really want good 8mil wires for my truck, but they're so expensive....

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