Step 3 » GENERAL learning environment Category B (B, B1)

GENERAL Learning Environment Category B (B, B1)
Question 658 of 1208

The presence of the carbon deposit on the surface of the spark plugs and the bluish smoke of the exhaust indicates:

A the engine mechanism (piston‑cylinder group) is worn;
B frequent driving with a speed lower than the legal limit;
C the use of unsuitable spark plugs.
Explanation

When the motor vehicle emits a bluish colour smoke and the spark plugs are covered with carbon deposit, it indicates an excessive oil consumption for lubrication, this is due to the fact that the engine mechanism (piston‑cylinder group) is worn and thus the oil for lubrication reaches the combustion chamber, where it should not normally reach. In this case you are recommended to contact a specialist.

The carbon deposit is a carbon residue resulting from the combustion of fuel in an internal combustion engine, which settles on the walls, on the spark plugs etc., causing disturbances in its operation.

The correct answer is: A


Recommendations:
Mechanics course (knowledge of the main elements) --> Mechanics course

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