Misfire in Cyl #4

[Plimbob]

Had a misfire code pop up for cylinder#4 in my 07 Tahoe (288,000). Pulled the plug and replaced which seemed to resolve for the time being. The plug was crusted white but didn't really look like it was the issue (tried upload picture but too large) at first glance.

What does the white crusting indicate - is that an indication of lean burn?

Thanks,
Tim

 

[wjburken]

Had a misfire code pop up for cylinder#4 in my 07 Tahoe (288,000). Pulled the plug and replaced which seemed to resolve for the time being. The plug was crusted white but didn't really look like it was the issue (tried upload picture but too large) at first glance.

What does the white crusting indicate - is that an indication of lean burn?

Thanks,
Tim

 

[Plimbob]

Thank Wade, the engine isn't overheating, these are the recommended ACDelco plug, I suppose it could have been loose but didn't feel like it when removed. I don't think I have a timing issue so it kinda leads me toward a possible lean mixture problem?

I did replace it and seems to be running smoother now but haven't driven it much since replacing.

 

[avalonandl]

Check it again in 10k miles.

 

[OR VietVet]

I would have pulled the plugs on each side of that cylinder to get a comparison. I would have also done a compression test while all 3 plugs were out. Hell, at 288k I would do a compression on all 8 cylinders.

 

[Plimbob]

Ron, not to be dense here but it comes easy for me - are you suggesting the plug comparison and compression check on cylinders 2 & 6 to see if there is a head gasket issue?

Thanks,
Tim

 

[OR VietVet]

I am suggesting the plug comparison to see if other plugs show maybe the same deposits and they just haven't triggered a code yet. I am also a guy that if had an engine with 288k on it and had a misfire and see deposits, I would do a compression. I have stated many times on here that I can spend other people's money for them quickly. I can also encourage more due diligence and work from other members as well. No sweat off my brow, so to speak. I like the full picture.

 

[Plimbob]

Ron - thanks for the info. Wasn't sure if there was something specific you were thinking.

Tim

 

[avalonandl]

At 288k that engine is on the "short" side of engine life.....

Hell I am suprised its running at all

 

[Plimbob]

Roger, I agree its on the downside of its lifecycle. But actually it runs pretty well all things considered. I bought it in 08 with 27,000 on it. Changed the oil every 3,000-3,500 without fail. I bought a Range AFM disabler at 120,000. In general tried to keep it maintained.

I've used it to pull my fishing boat all over the Midwest with never an issue - luckily.

Bought a 2017 replacement for her a few weeks ago, I may hand it down to one of the nephews....