MTC Preventive Maintenance Procedures 4

Question 1

During PM, a technician notices the marine engine's freshwater cooling system thermostat opens at 195°F but the engine continues to run at 210°F. What is the most likely cause?

Accepted Answer

Partial blockage in the heat exchanger or raw water circuit

Answer

A thermostat opening correctly but the engine still overheating points to restricted coolant flow, most commonly a fouled heat exchanger or blocked raw water strainer.

Question 2

When conducting PM on a vessel's steering system, what is the correct way to check hydraulic steering fluid level?

Accepted Answer

Check with steering centered and engine off after bleeding any air

Answer

Checking hydraulic fluid with the steering centered and engine off gives an accurate resting level reading and avoids false highs or lows caused by fluid displaced during turns.

Question 3

A PM inspection of a marine vessel's safety equipment reveals that flare expiration dates have passed. Under USCG regulations, what is the correct course of action?

Accepted Answer

Expired flares must be disposed of properly and replaced with current, unexpired USCG-approved signals

Answer

USCG regulations require that visual distress signals be current (unexpired); expired flares may be carried as extras but cannot count toward the required complement.

Question 4

When performing a compression test on a marine diesel engine during PM, which result indicates a worn or broken piston ring?

Accepted Answer

One cylinder reads significantly lower than the others, improving after adding oil (wet test)

Answer

Low compression that improves with a wet test (adding oil to the cylinder) indicates ring wear because the oil temporarily seals the gap the worn rings cannot close.

Question 5

What is the recommended torque sequence when re-installing a marine engine cylinder head after PM work?

Accepted Answer

Start from the center and work outward in a crossing pattern per OEM spec

Answer

Torquing from the center outward in a cross pattern ensures even gasket compression and prevents warping the head.

(MTC) Marine Technician Certification Practice Test

(MTC) Marine Technician Certification Practice Test

MTC Preventive Maintenance Procedures 4