Question

Blue smoke is caused by:

• A. Lubricant oil
• B. High load conditions
• C. Lean mixture
• D. Worn out piston rings

Hint:

Regular engine maintenance and timely replacement of piston rings can prevent the occurrence of blue smoke, which is a common sign of engine wear.

Answer 1

The Correct Option is D

Blue smoke from an engine exhaust usually indicates oil burning in the combustion chamber, which is often caused by worn-out piston rings. These rings fail to seal the oil below them, allowing oil to enter the combustion chamber where it burns and produces blue smoke.