The first one failed at around 90K miles, the second around 130000K, the third around 165000 and again this week at 167000K. I've changed spark plugs and plug wires. Always the same cylinder and the frequency has increased. I've checked the ground and the wiring harness for damage. Not sure where to go from here?

  • Welcome to Motor Vehicle Maintenance & Repair! What are you replacing them with? Aftermarket ones or OEM GM ones? And are your numbers correct? Looks like you are adding zeros. I would be highly surprised if you had gone 167 million miles in your truck, especially since the truck is only 6 years old. Instead of replacing it, have you tried moving it to a new location. IE: Exchange the "bad" coil with a known good one? It may be the plug is coming undone or something. – Pᴀᴜʟsᴛᴇʀ2 Aug 26 '18 at 12:32
  • Plug wires? I'm surprised that isn't a coil-on-plug motor. – 3Dave Aug 27 '18 at 18:00
  • @3Dave it’s coil near plug. To the OP maybe use an attenuator and min/max the coil ground see if there’s some kind of noise when it fires. – Ben Aug 28 '18 at 0:51
  • Is water getting under the hood and into the plug wires? Are wires routed near sharp metal edges like heat shields? Arcing to ground will kill those coil packs quickly. Run it in a dark garage with all the lights off and look for sparks to ground. – Chris Chubb Dec 4 '19 at 15:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.