Engine Repair (A1)Câu 4 / 120
On an overhead-cam engine, excessive valve lash (clearance) most commonly produces which symptom?
a.Blue exhaust smoke
b.Loss of coolant
c.Low oil pressure
d.A clicking or tapping noise from the valvetrain
Giải thích
Too much clearance in the valvetrain lets components hammer against one another, producing a rhythmic tapping that changes with engine speed. Insufficient lash, by contrast, can hold valves open and burn them. Proper adjustment restores quiet operation and correct valve timing.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
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