Engine Troubleshooting - Westerbeke BCGB Service Manual

BCGB ENGINE TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE VERIFICATION/REMEDY
ABNORMAL SOUND CRANKSHAFT AND MAIN BEARING
OR NOISE 1. Badly worn bearing. 1. Replace bearing and grind crankshaft.
2. Badly worn crankshaft. 2. Grind crankshaft.
3. Melted bearing.
3. Replace bearing and check lubrication system.
CONNECTING ROD AND CONNECTING ROD BEARING
1. Worn connecting rod big end bearing.
1. Replace bearing.
2. Worn crankpin.
2. Grind crankshaft.
3. Bent connecting rod. 3. Correct bend or replace.
PISTON, PISTON PIN, AND PISTON RING
1. Worn cylinder.
1. Rebore cylinder to oversize and replace piston.
2. Worn piston pin.
2. Replace piston.
. 3. Piston seized. 3. Replace piston and rebore cylinder.
4. Piston seized and ring worn or damaged. 4. Replace piston and rings.
VALVE MECHANISM
1. Worn camshaft.
1. Replace.
2. Excessive valve clearance.
2. Adjust.
3. Worn timing gear. 3. Replace.
4. Worn fan pulley bearing. 4. Replace.
LOW COMPRESSION
MAIN ENGINE TROUBLES
1. Incorrect valve clearance. 1. Adjust valve clearance.
2. Inadequate contact of valve seat.
2. Lap valve.
3. Valve stem seized.
3. Replace valve and valve guide.
4. Broken valve spring. 4. Replace valve spring.
5. Compression leaks through cylinder head gasket 5. Replace gasket.
6. Piston ring seized.
6. Replace piston and piston ring.
7. Worn piston ring and cylinder, 7. Overhaul engine.
S. Worn engine bearings. S. Overhaul engine.
EXCESSIVE FUEL
CONSUMPTION 1. Noisy knocking.
1. See KNOCKING.
2. Smoky exhaust.
2. See SMOKY EXHAUST.
3. Moving parts nearly seized or excessively worn. 3. Repair or replace.
4. Poor compression. 4. See LOW COMPRESSION; HARD STARTING.
5. Improper valve timing. 5. Adjust.
6. Improper valve clearance. 6. Adjust.
INSUFFICIENT INTAKE AIR
1. Air intake obstructed.
1. Remove obstruction.
NOZZLE TROUBLES
1. Seized nozzle. 1. Replace.
2. Worn nozzle.
2. Replace.
KNOCKING
ENGINE KNOCKS WITHOUT MUCH SMOKE
1. Main engine troubles.
a.Overheated cylinder. a. See OVERHEATING; LOW OUTPUT.
b.Carbon deposits in cylinder. b. Clean.
KNOCKING WITH DARK SMOKE
1. Poor compression.
1. See LOW COMPRESSION; HARD STARTING.
LOW OIL PRESSURE 1. Worn Bearings. 1. Engine overhaul replace bearings.
2. Relief valve malfunction. 2. Overhaul oil pump.
3. Clogged oil cooler/filter. 3. Repair and replace.
4. Diesel dilution of the oil. 4. Injection pump repair.
Engines & Generators
6