@Blueone
Actually, better yet would be to mix some Comet cleanser, Ivory liquid and then use an SOS pad like I did when I was a kid, baby sitting my siblings and tried to impress my mom by cleaning the badly stained porcelain kitchen sink.
Note to self: Do not mix chemicals when you don't know...
@rvlewis , you have just been adorned with the esteemed accomplishment of becoming the Grand Poobah and warehouse manger which includes monitoring the activity of this thread and edumacating the next guy.
The plug read and the oil sample are the what's. Let's find out the why.
Did your friend have any drivability, running or stalling issues this year or last?