2016 Mercedes-Benz AMG GT S Used Cars in Charlotte, NC 28212. Avg. Dealer Rating: (5 reviews) They have been so great, answered all of my questions and very patient with me when I wasn't immediately responsive due to illness. They worked everything out for an out-of-state sale.
By examining the spark plugâs insulator color, even a less-than-mechanically-inclined person can determine valuable information about the engineâs overall operating condition. Normal: Grey to Light Golden-Brown Color. This condition is ideal, the spark plug and engine air/fuel mixture are operating properly.
Coast to a safe stop on the return road, pull a spark plug out, and use the viewer to closely inspect the plug. Unleaded fuels do not color plugs as clearly as leaded fuels, so you have to look closely for the A/F ratio ring at the bottom of the center porcelain.