Which statement about idle and wear effects on engine components is most accurate?

• A. Excessive idling can glaze cylinder walls and cause piston rings to stick
• B. Long-idle periods strengthen piston rings
• C. Idling has no effect on cylinder walls
• D. Idling only affects valve seats

Answer: (A)

Idle operation keeps the engine at a低 temperature, so fuel and oil residues don’t burn off cleanly. Those residues can form a varnish or glassy glaze on the cylinder walls. That glaze changes the surface the piston rings ride against, reducing their ability to seal properly and often causing the rings to stick. Extended idling doesn’t strengthen rings; it can promote deposits and improper sealing. And the effects aren’t limited to valve seats—idle conditions can impact cylinder walls and other wear surfaces through deposits and lubrication issues.