Intermitttent Skip after New Plugs?

Hope you guys can help, 'cause I am stumped on how to figure this out... Did the full 30K service on my truck this morning, and after I started the truck, I noticed there was an intermittent skip while idling. It never did that before (of course), and I went one by one with the plugs, careful with the coils, made sure all the wires were plugged back up tight...everything I could think of. The only thing I can figure is I must have a bad plug, and it is not firing as it should.

Trouble is, I have no idea how to figure out which plug it is. I bought the plugs from the dealer, so I should have no problem swapping it for a new one. Any suggestions on finding the culprit? I would like to take it back to the dealer and have them do the diagnostic to find it, but that is probably not going to happen unless I cough up some cash and pay them to do it.

 

did you gap the plugs or leave them like them came?
I'd double check all the wiring to make sure you didn't leave something off

Out of curosity, why did you change the plugs already?

 

The plugs are due to be changed at 30K miles.

 

I checked the gaps, and all were .40. And I have 34K miles on it, and apparently have to be done to keep the emission control warranty good. But I change them anyway every 30K on all my vehicle, just for the sake of keeping everything running good.

 

I gotcha...I saw 2008 and assumed it was still ~20k miles.....
I don't put a lot of miles on my vehicles...

 

Ok. I will try again tomorrow morning, and do everything over again. As careful as I was, maybe I got some anti-seize on the electrode or something stupid like that. Thanks, and i will let you know how it comes out.

 

Went back through, check all the connections, checked all the plugs for gap, did find one that had a little smear of anti-seize on the electrode and got it cleaned off, buttoned it all back up and checked everything against Chris4x4's write-up...started the truck....still the intermittent skipping . This just boggles the mind. It runs fine while driving it, just while it idles it skips. Sometimes every few seconds, sometimes 7-10 seconds. Makes no sense.

 

pull one wire at a time while its running,see if you can see it spark

 

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No check engine light. The dealership thinks I might have a cracked plug, but I am not finding one. They told me if I can't get it figured out to bring it in the morning and they will see if they can sort it out, and if they have to, will hook it up and do a diag @ $79.

 

Well if you have the original plugs put those back in and see if the skip goes away, if it does then you likely have one plug with a hairline crack.

If the problem persists then it would likely be coil or connector on one of the plugs. A diag will identify which plug it is coming from then replace connector or coil as needed and or inspect and see if you can get a fix on the issue, could be something as simple as the spring in coil or something on the spring or connector contact loose.

 

Today's lesson: You will have a slight misfire, not enough to flip on the Check Engine light but enough to notice, if there is a spark plug not gapped right. I had my son helping me, and I checked all the gaps before installation and made sure all were correct, but he dropped on in the engine bay. Didn't think much of it as it was not a hard drop or anything, and we installed it...he helped check things out and apparently did not check the gap on that plug like I thought he did as he was looking for anti-seize on the electrode and physical damage to the plug. I did not follow behind him (totally my fault) since I had already watched him install all of them the first time and he did fine with it. But, dropping the plug did change the gap, and it caused the stutter in the engine. Plug replaced, gapped correctly, no more stutter. On the lighter side, had them check the noise in the rear suspension that appeared after they did the TSB and it was a loose shock bolt. So, the trip to the dealer was not a total waste, even though I still feel dumb for bringing a problem to the dealer I should have found myself. Thanks for all the great information and ideas on this site...I just need to make sure to follow behind my helpers from here on.

 

No kidding.
My previous car, the injector wires could get crimped and cause a misfire that'd go under the radar for normal usage but it'd show itself during extended idle.