2013 Impala 3.6 Cylinder 1 misfire.

[Blang]

My brother-in-law's car (2013 Chevy Impala with the 3.6 V6). Started this weekend running rough. My brother-in-law tried swapping coils to see if the misfire traveled. Nope. So he pulled cylinder 1 plug and it looked like this. He replaced the plug and now can't even get it to fire up. Will not run. I spent the afternoon today looking at it with him. Why would it get smashed like that?? I heard that carbon build-up can lead to that but I haven't made sense of that yet. Any thoughts? Thanks!

 

[Chris142]

Something got in there and hit it to do that.

 

[vw7674]

just look in the cylinder, broken valve bit is down there. carbon doesn't do that to sparkplugs.

 

[repairman54]

Compression test is in order to determine cylinder health.

 

[jmfx]

It started this morning but was knocking so I immediately shut it off. Here’s a pic of cylinder 1.