Skip to content
C1Difficulty 3/5

In an internal-combustion engine, what does persistent bluish-white exhaust smoke associated with high oil consumption usually indicate?

Correct answer

Engine oil is being burned.

It usually indicates oil burning in the engine. Possible causes include worn piston rings or valve-sealing components, but colour alone cannot identify the fault with certainty. Check consumption and follow manufacturer and workshop guidance. Oil consumption is not fuel consumption. Do not confuse it with temporary white condensation vapour or interpret every white plume as burning oil.

Practice more C1 licence questions

A self-check with exam-style questions on Mechanics and maintenance. Free, no signup.

All options

  • Any white smoke proves that the air filter is dirty.

  • Engine oil is being burned.

  • The colour identifies the exact faulty injector with certainty.

Editorial status: editorially approved. This status does not certify legal review. Report a correction

Share this question

Keep studying

Related questions