Dirty or contaminated oil system. Sticking piston rings or valve lifters.
Consumer solutions
Motor Cleaner
Only use for oil systemWynn’s Motor Cleaner is a highly concentrated detergent, designed to clean all oil lubricating systems prior to oil change.
Engine Flush
Only use for oil systemWynn’s Engine Flush is a highly detergent concentrate, designed to clean all oil lubricating systems prior to oil change.