Correct answer
Incomplete combustion due to insufficient air or too much fuel relative to available air.
Incomplete combustion and soot production, for example insufficient air or too much fuel relative to available air. A blocked air filter, intake fault or injection problem may be causes. The symptom does not by itself identify a failed component and does not mean the engine always compensates for insufficient air by injecting more fuel. Check the cause following manufacturer guidance.
Practice more C1 licence questions
A self-check with exam-style questions on Mechanics and maintenance. Free, no signup.
All options
Combustion that is always correct and produces no particles.
Conclusive proof that the only fault is in the engine piston rings.
Incomplete combustion due to insufficient air or too much fuel relative to available air.
Editorial status: editorially approved. This status does not certify legal review. Report a correction
Keep studying
Related questions
- A heat-exchanging mechanism, or intercooler, achieves...
- When leaving the driving position after parking a 6,000 kg MAM lorry with a manual gearbox on a noticeable 8% slope, besides stopping the engine and taking applicable precautions, what must you do?
- In a C1 or C truck, correct tire pressure:
- In a truck, preventive maintenance of the braking system is important because:
- A lorry has a body with insulated walls, doors, floor and roof to limit heat transfer, without a cold source or refrigeration equipment. Which type does this describe?
- For an engine with a toothed timing belt that runs dry, what belt maintenance should you follow?