A diesel engine is emitting black smoke, especially under load. Which of the following should be performed first?
A) check inlet restriction on fuel suction side
B) check air filter inlet restriction
C) check for high exhaust back pressure
D) perform an engine overhead adjustment

Question

Quizplus · Accepted Answer

Black smoke from a diesel engine, especially under load, typically indicates incomplete combustion due to insufficient air. Checking the air filter inlet restriction (B) should be the first step, as a clogged air filter can significantly reduce the amount of air available for combustion, leading to the production of black smoke.

A Diesel Engine Is Emitting Black Smoke, Especially Under Load