A customer needs new spark plugs. They bring in their old ones, and you see that they’re very dirty with oil. What is a likely cause for this?
A) Improper reach in spark plugs may be permitting the piston to touch the firing end.
B) The air/fuel mixture is too rich.
C) Too much oil is entering the combustion chamber, possibly because of damaged piston rings or cylinder walls.
D) The spark plug temperatures were raised too high due to hard, fast acceleration.