Intermittent misfire at low RPMS

AlphaZulu · Dec 7, 2024

Fless said:
Hope the new plugs are the same, because the ones you removed are way mismatched. Nos. 1 & 5 were a different heat range than the others.

@Rocket Man shows the tool setup for the #8 plug:

spark plug change 5.3

So i decided to change my plugs on my 2008 Tahoe after a 125,000 miles, the driver side easy to do but the passenger side little more difficult. So i removed the inner wheel well liner and used my dewalt clamp to push the AC lines up to access the rear plug, see pic. Hope this helps someone.

www.tahoeyukonforum.com

I didn't notice that until I was uploading the pictures, and now I'm second guessing my order. I think I probably have them reversed, and the two wrong ones are #3 & 7, which were my misfire cylinders. So much for government maintenance. The new plugs are all matched and correct.

Nice catch.

Doubeleive · Dec 7, 2024

AlphaZulu said:
Well, I got cylinders 1-7 done, and have enormous respect for anyone that can get #8. Worthy of note is that #7 had an aftermarket plug wire made by Packard with a 90° elbow on the plug end. This pushed the wire up against the exhaust manifold heat shield, and I believe this was the cause of my misfire. After changing (almost) all of the plugs and wires the vehicle runs smooth and strong.

Thanks again for the advice OR VietVet & Doubeleive

8 is easy, just put the plug socket on it, adapt it down to 1/4" get a 1/4 angled head ratchet, attach a small breaker bar to said ratchet, pop it loose. that is 99% of the job right there. i score high on mechanical ability but low on brain power lol

OR VietVet · Dec 7, 2024

Like @Doubeleive said. It is not hard to do with the right tools. You can also use a spark plug socket that has a 6 point on the head and then use a short socket on that or a small wrench to break loose.

AlphaZulu · Dec 7, 2024

I'll have to revisit this when I get better tools and/or smaller hands. I couldn't even get my hands in close enough to get a decent grip on the plug wire, and was pretty sure if I got it off/out I wouldn't be able to get the new one back in/on. I appreciate all the tips and advice, and I will get this done sooner or later. For now I'm very happy to have all 8 cylinders back, and disappointed in the US NPS maintenance crew.

Tahoe14 · Dec 7, 2024

They make special pliers to remove and reattach spark plug wires.

Intermittent misfire at low RPMS

AlphaZulu

TYF Newbie

spark plug change 5.3

Doubeleive

Wes

OR VietVet

Multnomah Falls

AlphaZulu

TYF Newbie

Tahoe14

Full Access Member

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