Engine Repair (A1)Question 10 of 120
Blue smoke from the exhaust under acceleration most often indicates:
a.A rich fuel mixture
b.Coolant in the combustion chamber
c.Oil entering the combustion chamber
d.A lean misfire
Explanation
Blue smoke indicates oil is being burned, commonly from worn rings, cylinder walls, or valve guide seals. White smoke suggests coolant, and black smoke suggests excess fuel. A leak-down or compression test helps localize the source.
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