Misfire?

2008 GMC SIERRA
250,000 MILES • 5.3L
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KJ
  • MEMBER
  • 1 POST
I was told this could be a DOD problem, but I don't believe it is because there's no lifter ticking. I pulled the plug wires off one at a time and found two cylinders down. I replaced the coil, and it did not change anything. Someone told me that I would need to clear the code afterwards, but I have not tried that.
Jul 11, 2022 at 4:59 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

Did you check if the affected cylinders are getting spark even with the new coils? Also, what codes are you getting?

As far as clearing the code, that won't change a misfire. If the problem was solved, you would feel the difference.

Do me a favor. First, confirm there is spark to the affected cylinders. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Also, let me know what codes you find.

Take care,

Joe
Jul 11, 2022 at 10:12 PM
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