The main propulsion diesel engine jacket water temperature rises above normal, with the raw sea suction and the expansion tank water level being normal. Which of the following problems is most likely the cause?

A．Faulty thermostatic bypass valve

B．Eroded zinc pencils in the heat exchanger

C．Steam formation in the expansion tank

D．Excessive leakage from jacket water pump seals

[单选题]In a main propulsion turbocharged diesel engine, the speed of the turbocharger varies according to the _____.A．governor droopB．speeder spring tensionC．fuel rack lagD．load on the engine

[单选题]Diesel engine jacket water is used in the distillation process as the （）.A . coolant for the distillateB . coolant for the brine coolerC . means of heating the feedwaterD . primary means of producing a vacuum within the distiller

[单选题]The main propulsion diesel continues running after you try to shut down. You should now attempt to .A．stop the fuel oil booster pumpB．engage the jacking gearC．secure the lube oil pumpD．shut off the fuel at the settling tank

[单选题]Control of the main propulsion diesel engines can be shifted from the engine room to the wheelhouse from the （）.A . wheelhouse control stationB . engine room control stationC . captains officeD . chief engineers office

[单选题]On a medium-speed main propulsion diesel engine, the crank-pin or crank journal bearings receive lubricating oil from （）.A . a spindle lubricatorB . an oil jetC . internal splashingD . drilled passages in the crankshaft

[单选题]The main moving parts of a diesel engine consist of the （） and the pistons.A . bedplate, connecting rodsB . crankshaft, the connecting rodsC . frames, crossheadsD . crankshaft, the cylinder

[单选题]For a main diesel engine the lube oil in the bearings is drawn from （）, usually located in the bedplate.A . a gravity tankB . a sumpC . a vesselD . a bottle

[单选题]Diesel engine main and connecting rod precision bearings are made in halvesEach half exceeds one-half the bearing circumference by a small amountThe small amount is termed （）.A . clearanceB . crushC . pitchD . thrust

[单选题]F．or most diesel propulsion and generator engines, the over-speed trip device will stop the engine byA．moving the governor control to stopB．shutting off the lubricating oil supplyC．tripping the governor emergency stop leverD．shutting off the fuel sup

[单选题]The jacket water temperature in a diesel engine closed freshwater cooling system is normally controlled by （）A . regulating the level of corrosion inhibitor in the primary cooling systemB . the level of the freshwater expansion tankC . varying the en