Cylinder Misfire

[Brian 162]

I have a question for the brain trust.
In the fall I replaced the spark plugs on my 17 Tahoe with a 5.3 engine. Since then I've driven around 7000 miles including driving to Arizona and back.
Everything was fine until a week ago (22nd) after I got an oil change at the dealer a week before on Feb 15.
The vehicle started shuddering and the check engine, traction control and forward collision alert lights came on
I took the vehicle to my indy mechanic which is over an hour away from me. Long story short it was a loose wire at cylinder 7 that was arcing.
My question is could the wire/boot have loosened off that much or did the dealer inadvertently hit the wire.
The reason why I suspect the dealer is the tech checked the cabin and engine air filter.
I was asked if I wanted replacement of both, I declined.
They didn't put the cabin filter housing together properly including leaving a screw on the floor and one loose.
One of the air filter bolts wasn't tightened, oh the air filter was fine.Sorry for the long rant but what do you think?


Thanks in advance
Brian

[manbridge 74]

Probably unrelated as the air filter is far away from plugs, but maybe a tool was dropped? Any visible damage? My 16 Suburban 5.3 has had zero issues from new. 160k miles. I finally did plugs at 150k, they looked great but a lot of unnecessary wear and tear happens to ignition systems with old large gap plugs. The wires are robust.

[Arizona_928]

Anything is fair game now in days.


Very rare to have a spark plug wire come lose on that platform. And I’ve abused a lot of 4.8/5.3/6.0 engines

[Brian 162]

Everything looked fine. It was cylinder #7 which was the culprit. I changed the plugs at 100,000 miles.
What irked me was the way they left the cabin/air filter housings.
It could have been coincidental.
Thanks yo you both for replying.

[masraum]

Originally Posted by Brian 162

Long story short it was a loose wire at cylinder 7 that was arcing.
My question is could the wire/boot have loosened off that much or did the dealer inadvertently hit the wire.

LOL! Inadvertently. You crack me up, sir. Good one!


On a more serious note, Hanlon's Razor may be best applied here, "never attribute to malice that which is adequately explained by stupidity."

Although, in certain circumstances, my mind does tend to think malice may be a factor. I had an issue at a shop many years ago. I'm 99% sure that in my case it was due to incompetence, not fraud, but in my case, it was incompetence of such a level that it bordered on fraud.

In your case, if that wire isn't any where near anything that they were working on, then my mind would assume fraud, but I have a tendency to give folks the benefit of a doubt. What I'd probably (usually) do is just never take my vehicle back to that shop.

[Brian 162]

^^^^^
Steve
That's the plan take it somewhere else.
Problem is, we recently moved and my indy mechanic is now 75 miles away but they're really good and take care of me. I only use him a couple times a year to go over the vehicle and fix what I can't handle
I may start to do oil/filter changes again

[Baz]

Sounds very fishy to me, Brian. I've had my '02 4.8 Silverado since '05, and have never had a plug wire come loose on it's own!

I'd be pissed as well about the sloppy work on the air & cabin filter!

[Brian 162]

^^^
I know Baz, it doesn't pass the smell test.

[Tobra]

Letter to corporate

[cockerpunk]

stop doing cheap oil changes.

do them yourself.

basically thats why i stopped taking things to shops.

[Arizona_928]

Originally Posted by cockerpunk

stop doing cheap oil changes.

do them yourself.

basically thats why i stopped taking things to shops.

I put in fumoto drian plugs in all my toys. No spill/mess oil changes…

[908/930]

He did the oil change at a dealer I doubt it was cheap. Hard to prove anything but don't go back there. Once off warranty no good reason to use dealer. My 2500hd has a recall for passenger airbag and I don't want to bring it to a dealer but no choice.

[Zeke]

I forget which side the furthest plug back is but seems to me the right side looking forward. I had to use a few different extensions 'during' the removal and installation of that plug. Getting the wire off and on was just as bad. You could have done this yourself. It's not easy to know when the cap is completely snapped in place.

An interesting thing about plugs. I got new ones at 80,000 and bought a different brand listed as correct for the 4.8 V8. Not cheap either. The engine ran slightly rough, just a bit, but it was enough to be annoying in that I was used to not even hearing it, much less feeling it. Went back to new factory plugs and it ran perfectly w/o a single adjustment.

Go figure.

[Brian 162]

Originally Posted by cockerpunk

stop doing cheap oil changes.

do them yourself.

basically thats why i stopped taking things to shops.

It was at a Chevrolet dealership, I paid $130

[Brian 162]

Originally Posted by Tobra

Letter to corporate

I sent one to the service manager and mentioned it to the service adviser, nothing but crickets.

[Brian 162]

Originally Posted by Zeke

I forget which side the furthest plug back is but seems to me the right side looking forward. I had to use a few different extensions 'during' the removal and installation of that plug. Getting the wire off and on was just as bad. You could have done this yourself. It's not easy to know when the cap is completely snapped in place.

An interesting thing about plugs. I got new ones at 80,000 and bought a different brand listed as correct for the 4.3 V8. Not cheap either. The engine ran slightly rough, just a bit, but it was enough to be annoying in that I was used to not even hearing it, much less feeling it. Went back to new factory plugs and it ran perfectly w/o a single adjustment.

Go figure.

You are correct. Cylinder 7 is on the passenger side close to the firewall. I died a horrible death changing that plug. I had to snake my arm between the battery and the a/c lines. Chewed both my arms.
I ended up installing the plug from the bottom. I checked the boot at least 5 times before doing the other plugs.
That's why I can't figure out how this happened 4 months after I did the work.

[pwd72s]

I'm the suspicious sort, but sounds to me that you very well could have been set up for a return visit..

[1990C4S]

Regardless of what happened to your spark plug boot, you should not go back to that dealer. They did crap work, and they ignored your complaint.

Beyond that, what's left to discuss?

[Brian 162]

Originally Posted by pwd72s

I'm the suspicious sort, but sounds to me that you very well could have been set up for a return visit..

The cynic in me agrees with you

[RANDY P]

First and only time I took my Vette to the local dealer (who got decent reviews, go figure) managed to screw up every single seat and HVAC setting and got oil on the windshield.

A dealership especially a domestic one is $hit- none of 'em are worth paying. Sloppy work and they treat the customers like trash. Give your business to a smaller shop where the owner works on cars and actually cares about their reputation.