Crack in Spark Plug?

[Scupper]

2000 GMC Yukon XL 5.3 207,000. 60,000 miles on spark plugs.

3 miles out of my garage, the "service engine soon" light illuminates and is intermittently flashing. I was at freeway speed and approaching my destination. Upon sitting at the signal light waiting for it to turn green so as to proceed, I noticed the engine bucking with a miss.

Turned out that the porcelain part of one of the spark plugs was cracked. Any theory's or thought's as to this. Was also told that the engine is tired...Any thoughts to this?

She get's regular scheduled service and runs like a top.

Thanks for any information, thoughts or opinions.

Scott

[Whoaru99]

Hard to say. Any other repair history where something might have got hit?

About tired...well, it's all relative. If it seems to run good otherwise I'd replace the plugs and what ever else is commensurate/about due for the mileage (wires, cap & rotor (does a 2000 even have those?) with the mileage and carry on.

[Scott K]

+1

Fix the plug, do some maintenance, and drive it until it doesnt run anymore. Weak? If you havent noticed it, dont worry about what they told you.

[Macgyver55]

A cracked plug isn't all that uncommon although its less common now than in the past. Spark plugs are pretty amazing little devices that last a very long time for what they do and for what they cost. Think about being in a pressurized chamber that has a fiery explosion anywhere from a few hundred, to six thousand (or more) times a minute and do it for years on end most of the time and with out fail. I'm amazed there are not far more plug failures than there are.

Put in a new one and drive it.......

[Scupper]

Quote:

Weak? If you havent noticed it, dont worry about what they told you.

I have noticed that I have to stick my foot into it more then used to but I usually drive it like a guy in his late 50's should.

New plugs, wires and scheduled oil change done.

I do drive them until last rights are performed. Last one was pronounced deceased up at Northome, 2006 on my way home from Lake of the Woods - 240,000 miles.

I sure would like to get more miles then that on this one as I have really babied her...