Question 16Motor Plants - 1st Asst/Chief

The correct answer is C) Leaky exhaust valve. When one cylinder has a lower compression pressure and higher exhaust gas temperature than the other cylinders, it indicates that the exhaust valve on that cylinder is leaking. This allows some of the high-pressure, high-temperature exhaust gases to escape back into the cylinder during the exhaust stroke, resulting in lower compression and higher exhaust temperatures for that cylinder compared to the others. The other options are incorrect because they do not adequately explain the specific symptoms described in the question. Advanced ignition, a clogged air intake, or high exhaust pressure would not necessarily result in the uneven cylinder performance observed here.