Engine Repair (A1)Question 3 of 120
A valve that fails to seat fully will most directly cause which condition?
a.Low cylinder compression on that cylinder
b.Excessive oil consumption only
c.High oil pressure
d.A stuck lifter
Explanation
A valve that does not seat allows combustion pressure to escape, lowering compression in that cylinder and often causing a misfire. A cylinder leak-down test with air hissing from the intake or exhaust confirms an intake or exhaust valve leak. Burned valves and carbon deposits are common causes.
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