Trouble Shooting Engine

Marine Diesel Engines

Trouble Shooting

Engine Fails to Turn on Air?
Possible causes?
Low air pressure.
Sticking start air valves.
Starting valve leaking.
Pilot valve closed.
Starting air to distributor valve shut.
Distributor failure.

Engine Fails to Fire?
Possible causes?
Air in fuel system.
Blocked filters.
Blocked pipes.
Fuel injection pump incorrectly set.
Fuel bypass open.
Booster pump failure.
Air compression too low.
Fuel tank empty.
Water in fuel.

Fuel circulation

Compression Pressure Low?
Causes?
Worn or broken piston rings
Leaking cylinder valves
Leaking cylinder head gasket

Engine Stops Unexpectedly?
Possible causes?
Air in fuel system.
No fuel.
Failed fuel supply pumps.
Water in the fuel.
Blocked filters or fuel lines.
Engine seizure.

Engine RPM Drops?
Possible causes?
Engine overload.
Faults in fuel supply system.
Air in the fuel.
Fuel restriction.
Auto initiated slow downs.
Turbo charger filter clogged.
Valve clearances.

Engine Knocking
Possible causes?
Injection too early.
Faulty injectors.
Metal to metal contact.
Worn bearings.
Worn liner.
Overload.

Abnormally High Exhaust Temperature One Cylinder?
Possible causes?
Late injection.
Low injector opening pressure.
Leaky injection valve.
Exhaust blockage.

Abnormally Low Exhaust Temperature One Cylinder?
Possible causes?
Insufficient fuel.
Early injection.
High injector opening pressure.
Water in fuel.

Abnormally High Exhaust Temperature All Cylinders?
Possible causes?
Engine overload.
Late injection.
High charge air temperature.
Low charge air pressure.
Blocked air intake filter.
Blocked exhaust.

Black Exhaust Gas?
Possible causes?
Engine overload.
Reduced scavenge air.
Faulty injection system.
Late injection.
High fuel temperature.
Poor quality fuel.

Blue Exhaust Gas?
Possible cause?
Excessive cylinder lubrication.

White Smoke?
Possible cause?
Cold engine.
Water in cylinder.
Excess air.
Insufficient fuel.
Low compression.

Lub Oil Pressure Falling?
Possible causes?
Low sump level.
Blocked filters.
Internal leakage.
Damaged bearing.
High oil temperature.
Sticking pressure control / relief valve.
Lub oil dilution.

Overheated Bearings?
Possible causes?
Reduced oil supply.
Reduced bearing clearance.
High lub oil temperature.
Dirty cooler.

High Jacket Water Temperature?
Possible causes?
Dirty heat exchanger.
Engine overload.
Air in system.
High sea water temperature.