Question 143Motor Plants - 1st Asst/Chief

The correct answer is A) long periods of engine overload. Prolonged engine overload can lead to excessive heat buildup, which can cause damage to fuel injection nozzles. This is because the high temperatures and pressures associated with engine overload can cause the nozzles to overheat, leading to heat-related damage such as warping, coking, or carbon buildup. Avoiding extended periods of engine overload is a crucial step in preventing this type of heat damage to the fuel injection system. The other options are incorrect because: B) metallic contact between nozzles and cylinder heads is not a direct cause of heat damage, C) hard carbon deposits and varnish are symptoms of heat damage rather than a cause, and D) excessive fuel oil temperature is a result of heat damage, not a cause.