Cylinder #1 Misfire

[sierra5454]

I have 2012 GMC Sierra 5.3.  Had to have new engine installed under warranty about 1.5 years ago.   2 days ago it started running rough at idle and eventually threw the cylinder 1 misfire code.  I swapped plugs 1-3 and misfire went to cylinder 3 with the plug.  The plug from cylinder 1 was fouled and oil'd up.  After replacing the plug last night.  The rough idle and code has stayed away.  I also cleared all codes with a scan tool.  

 

My question is... am I looking ahead for something bad.  What would cause all that oil on the plug.   I drove it for about 2 days with the misfire.  The replacement engine only has about 25k on it.  Plug on left is from #3  right was #1.

[carnau]

I actually made a video about this! So here you go. In the video it is on Cylinder number 7. But 1 and 7 are the two that foul out.

 

Here are the parts you need.

Valve cover - http://amzn.to/2C5MIhd

41-110 Spark Plug - http://amzn.to/2E8oD71

 

Make sure you like and subscribe to my youtube channel while you are at it.

 

 

 

[DaddyBird]

WIll this fix the problem on a 2013 silverado xfe?

5.3L

code 015b

just replaced plugs and wires. Is this something I should do also?

[Michael D Harrell]

I pulled and replaced the valve cove rsame problem. When I have the valve cover off I noticed the push rod closest to the front was sloppy is it bent?