Question 583Steam Plants - Assistant Engineer

The correct answer is D) high temperature of the lube oil leaving the bearing. An overheated bearing in the main propulsion unit is indicated by a high temperature of the lube oil leaving the bearing. This is because an overheated bearing generates excess heat, which is then transferred to the lube oil as it circulates through the bearing. The high temperature of the lube oil leaving the bearing is a clear sign that the bearing is overheating and may require attention or maintenance. The other answer choices are not direct indicators of an overheated bearing. Bubbles in the sight flow glasses (A) may indicate other issues, such as air entrainment in the lube oil system. Sludge in the lube oil strainers (B) and a high level in the lube oil sump (C) are more general indicators of lube oil system problems, but do not specifically point to an overheated bearing.