The troubleshooting guide (table 5-1) is provided as an aid to locate and correct any malfunctions of the die- sel engines. At the first sign of trouble, isolate the problem and evaluate before removing any components.Table 5-1represents a list of potential problems, their probable causes, and suggested corrective actions.
Table 5-1. Troubleshooting Guide
Problem/Malfunction Probable Cause Corrective Action
Engine will not crank. a. Loose or corroded battery cables.
a. Clean and tighten battery connections.
b. Loose or corroded connections in the starting circuit
b. Clean and tighten connec- tions.
c. Battery charge low. c. (1) Inspect battery for dead cell. Replace defective battery. (2) Inspect alternator output. Replace defective alternator. d. Faulty solenoid or starting
motor.
d. Temporarily cross-connect the starter solenoid terminals If the starter does not crank, replace the starter motor. e. Faulty auxiliary magnetic switch. e. Temporarily connect starter
solenoid terminal P to S. if the engine does not crank, replace the switch.
f. Faulty starter switch. f. Temporarily connect termi- nals I to S on the start switch. If the starter cranks, replace the switch.
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
2. Engine cranks but will not start (no smoke from exhaust).
a. No fuel in supply tank. a. Replenish fuel supply. b. Electrical or manual fuel shut-
down not open.
b. Inspect for loose wires; ensure the valve is operating. The manual shutoff valve must be in the run position.
c. Air intake or exhaust plugged. c. Remove obstruction. d. Fuel filter plugged or water con-
taminated.
d. Drain fuel/water separator and replace fuel filter. e. Injection pump not receiving
fuel or air in fuel.
e. Inspect fuel flow and bleed air from fuel system.
f. Worn or faulty injection pump. f. Check fuel delivery. Replace pump, if necessary.
g. Internal pump timing incorrect. g. Time the pump.
h. Camshaft out of time. h. Correct gear train timing. 3. Engine cranks but will not
start (smoke from exhaust).
a. Incorrect starting procedure. a. Ensure the EEOP is used to stan engine.
b. No fuel in supply tank. b. Check fuel supply; replenish as necessary.
c. Electric or manual fuel shutdown not open.
c. Ensure solenoid is energized. If no voltage, inspect for bro- ken wires. If voltage is present, inspect shutdown solenoid operation. Replace defective parts.
d. Exhaust restriction. d. Locate and correct any exhaust restriction. e. Fuel filter plugged or contami-
nated.
e. Drain fuel/water separator and renew fuel filter element. f. Injection pump not receiving fuel
or air in fuel.
f. Inspect fuel flow and bleed air from fuel system.
g. Worn or faulty pump. g. Replace injection pump. 4. Engine hard to start or will
not start (smoke from exhaust).
a. Engine under load. a. Ensure clutch or transmis- sion is disengaged.
b. Incorrect starting procedure. b. Refer tochapter 2. c. Cranking speed too low/slow. c. (1) Inspect battery, starting
motor for loose or corroded wiring connections. Clean and tighten connections.
(2) Bar engine over to check for excessive resistance. d. Crankcase heater not working. d. Check power source, ther-
mostat and heater to ensure heater is operating properly. Replace defective parts. e. Insufficient intake air. e. Inspect/replace air filter and
check for obstructions. f. Air in fuel system. f. Bleed air from fuel system.
Determine cause of air in sys- tem and correct.
S9233-C9-MMA-010
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
g. External pump timing incorrect g. Ensure pump timing marks are in alignment and timing is correct.
h. Contaminated fuel. h. Drain and flush fuel supply tanks. Refill with clean fuel oil. i. Injection nozzles worn or faulty. i. Inspect and replace injection
nozzles, as necessary. j. Valves incorrectly adjusted. j. Adjust valves.
k. Worn or faulty injection pump. k. Replace injection pump. 5. Engine starts but will not
keep running.
a. Low fuel level in supply tank. a. Replenish fuel supply, as necessary.
b. Broken or loose correction to shutdown.
b. Inspect shutdown wiring and repair, as necessary.
c. Restricted exhaust. c. Inspect and correct exhaust restriction
d. Fuel restriction in the suction side of the fuel system.
d. Remove restriction, e. Restricted fuel drain manifold or
return line.
e. Remove restriction. f. Fuel system leak/air in fuel sys-
tem.
f. Visually inspect fuel system for leak and correct leakage. Bleed air from fuel system. g. Contaminated fuel. g. Drain and flush the fuel sup-
ply tank. Refill with clean fuel oil.
h. Injection nozzles worn or faulty. h. Inspect and replace nozzles, as necessary.
i. Worn or faulty injection pump. i. Replace injection pump. 6. Surging (speed change). a. If at idle, idle speed is set too
low.
a. Adjust idle speed.
b. High-pressure fuel leak. b. Inspect and correct leaks in high-pressure fuel lines, fit- tings, nozzle sealing washers, or delivery valves.
c. Worn or faulty injection nozzles. c. Replace nozzles, as neces- sary.
d. Faulty delivery valve. d. Replace delivery valve. e. Faulty injection pump. e. Replace injection pump.
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
7. Rough idle. a. Cold engine. a. Refer to Coolant Tempera- ture Below Normal.
b. Idle speed too low. b. Adjust low idle screw. c. Engine mounts overtightened,
damaged, or loose.
c. Inspect condition of mounts. Replace, as necessary.
d. High-pressure fuel leak. d. Correct leaks in high- pressure lines, fittings, injection sealing washers, or delivery of valve seals.
e. Air in fuel system. e. Locate and correct source of air in fuel system. Bleed air from fuel system.
f. Sticking needle valve in nozzle. f. Replace injection nozzle. g. Faulty delivery valve. g. Replace delivery valve. h. Valves not seating. h. Adjust valves.
i. One or more cylinders losing compression.
i. Perform compression check and repair, as necessary. 8. Engine runs rough or misfir-
ing.
a. Fuel injection lines leaking. a. Repair leaks in high-pressure lines, fittings, nozzle seal washers, or delivery valves. b. Air in the fuel or the fuel supply
is inadequate.
b. Inspect flow rate and bleed air from the system.
c. Contaminated fuel. c. Drain and flush fuel supply tanks. Refill with clean fuel oil. d. Incorrect valve adjustment. d. Inspect for bent push rod
and readjust valves. e. Injection pump timing incorrect. e. Time pump.
f. Low compression. f. Perform compression check and repair, as necessary. g. Faulty injection nozzle. g. Replace nozzle. h. Defective injection pump. h. Replace pump. i. Camshaft out of time. i. Retime gear train. j. Damaged camshaft or tappets. j. Inspect camshaft replace
parts as necessary. S9233-C9-MMA-010
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
9. Engine will not reach rated speed.
a. Engine overloaded. a. Verify high-idle speed with- out load. Reduce engine load. b. Faulty tachometer. b. Ensure correct engine speed
with hand tachometer. Replace tachometer or sending unit, if necessary.
c. Throttle linkage worn or improp- erly adjusted.
c. Replace or adjust linkage for stop fuel control lever travel. d. High-speed stop screw incor-
rectly adjusted.
d. Reset high-speed stop screw. e. Mechanical shutdown lever par-
tially engaged.
e. Reposition shutdown lever in run position
f. Inadequate fuel supply. f. Inspect the fuel flow. Locate and correct the source of the restriction.
g. Restricted manifold drain line, if condition is intermittent
g. Remove restriction. h. Faulty injection pump. h. Replace pump. 10. Low power. a. Fuel control lever not moving to
full speed.
a. Ensure throttle travel is from stop-to-stop.
b. Mechanical shutdown lever par- tially engaged.
b. Place shutdown lever in run position.
c. High oil level. c. Reduce oil level to correct mark on dipstick.
d. Engine overloaded. d. Inspect for added loading from faulty accessories or marine gear. Repair, as neces- sary.
e. Incorrect external injection pump timing.
e. Ensure pump timing marks are aligned.
f. Air intake air inadequate or too high or low in temperature.
f. Replace air cleaner element. Correct any restrictions. g. High-pressure fuel leak. g. Correct leaks in high-
pressure lines, fittings, nozzle sealing washers, or delivery valve seals.
h. Inadequate fuel supply. h. Inspect the fuel flow through the filter to locate the source of the restriction.
i. High fuel temperature. i. Ensure fuel heater is off in warm weather.
j. Restricted fuel drain manifold (if low power is intermittent).
j. Correct restriction.
k. Poor quality fuel. k. Operate engine from a fuel tank known to have good fuel. l. Valve clearances incorrect. l. Adjust valves.
m. Injection pump internal fault. m. Time pump.
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
n. Low compression. n. Perform compression check to determine faulty cylinders. Repair as necessary.
o. Worn or faulty injection nozzles. o. Inspect nozzles. Repair or replace, as necessary. p. Faulty injection pump. p. Replace injection pump. q. Excessive exhaust restriction. q. Repair exhaust system, as
necessary. r. Model 6BT5.9-M malfunctioning
turbocharger.
r. Inspect/replace, as necessary. 11. Excessive exhaust smoke
(white smoke).
a. Engine running too cold a. Refer to Coolant Tempera- ture Below Normal,
b. Inadequate air intake. b. Change air cleaner element; inspect and repair any other restrictions.
c. Model 6BT5.9-M air leak at tur- bocharger.
c. Locate/correct turbocharger air leak(s).
d. More than one sealing washer under nozzle.
d. Remove extra washer. e. Model 6BT5.9-M malfunctioning
turbocharger.
e. Replace turbocharger. f. Faulty injection nozzles. f. Replace nozzles. g. Faulty or overfueled injection
fuel pump.
g. Replace injection pump. h. Piston rings not sealing (blue
smoke).
h. Perform compression check and correct any deficiency dis- covered.
12. Coolant temperature above normal.
a. Low coolant level. a. Replenish coolant as neces- sary. Repair any coolant leaks. b. Faulty pressure cap. b. Replace pressure cap. c. High lube oil level. c. Drain oil to correct level on
dipstick.
d. Loose drive belt on water pump. d. Adjust belt tension. e. Inadequate sea water flow to
heat exchanger.
e. (1) Inspect sea water suction for debris. Clean, as necessary. (2) Check sea water pump out- put. Rebuild or replace pump, as necessary.
f. Heat exchanger plugged. f. Clean heat exchanger. g. Faulty temperature gauge. g. Ensure the gauge is accu-
rate; if not, replace the gauge. h. Faulty, incorrect, or no thermo-
stat
h. Replace thermostat.
i. Air in cooling system. i. (1) Ensure correct thermostat installed.
(2) Inspect for head gasket leak.
j. Faulty water pump. j. Replace water pump. S9233-C9-MMA-010
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
k. Incorrect injection pump timing. k. Time injection pump. l. Incorrect external injection pump
timing.
l. Ensure pump timing marks are aligned.
m. Plugged cooling passages in head, head gasket, or block.
m. Flush the system and fill with clear coolant.
n. Engine overloaded. n. Reduce engine load and speed.
13. Coolant temperature below normal.
a. Incorrect thermostat, broken jiggle pin, or contamination in the thermostat.
a. Replace thermostat.
b. Temperature sensor or gauge faulty.
b. Ensure the gauge and sensor am accurate. Replace as neces- sary.
c. Coolant not flowing by tempera- ture sensor.
c. Clean coolant passages in block.
14. Coolant loss. a. External leak. a. Inspect engine and compo- nents for leaking hoses or gas- kets. Repair all leaks.
b. Transmission cooler leak. b. Inspect transmission sump for coolant. Replace cooler if leaking.
c. Lube oil cooler leak. c. Inspect for coolant in oil sump. Replace cooler. d. Head gasket leak. d. Replace head gasket. e. Cracked or porous head. e. Replace head. f. Leak in cylinder block coolant
passages.
f. Replace the cylinder block. 15. Lubricating oil pressure
low.
a. Low oil level. a. Replenish oil to proper level on dipstick. Repair oil leaks. b. Oil viscosity thin, diluted, or
wrong specification.
b. Ensure correct oil is being used. Refer totable 2-2. c. Faulty pressure switch or gauge. c. Ensure the pressure switch
and gauge are functioning cor- rectly. Replace faulty switch or gauge.
d. Relief valve stuck open. d. Replace valve. e. Plugged oil filter. e. Change oil filter. f. Shipping plugs left in cooler (if
cooler was replaced).
f. Remove plugs. g. incorrect lube oil pump installed
(if replaced).
g. Replace with correct pump. h. Loose or missing cup plugs. h. Replace cup plugs.
i. Suction tube loose/seal leaking. i. Replace seal. j. Worn lube oil pump. j. Replace pump.
k. Loose main bearing cap. k. Install new bearings and torque cap.
l. Worn bearings. l. Replace bearings; replace piston cooling nozzles.
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
16. Lube oil pressure too high. a. Faulty pressure switch or gauge. a. Ensure pressure switch and gauge are functioning correctly. Replace if necessary.
b. Engine running too cold. b. Refer to Coolant tempera- ture below normal.
c. Oil viscosity too thick. c. Ensure correct oil is being used.
d. Relief valve stuck closed. d. Replace valve. e. Incorrect lube oil pump installed
(if replaced).
e. Replace with correct lube oil pump.
17. Loss of lube oil. a. External leaks. a. Inspect for leaks and correct as necessary.
b. Crankcase overfilled. b. Drain oil to correct level on dipstick.
c. Incorrect oil. c. Ensure oil is correct viscos- ity. Test oil for fuel dilution. d. Oil cooler leak. d. Inspect for oil in coolant.
Replace cooler. e. Excessive blow-by forcing oil
out of the breather.
e. Measure blow-by and cor- rect as necessary.
f. Worn valve seals. f. Replace valve seals.
g. Worn piston rings. g. Perform compression check. Replace piston, rings, as neces- sary.
h. Model 6BT5.9-M turbocharger leaking oil into the air intake.
h. Inspect model 6BT5.9-M turbocharger for faulty seals. Replace seals, as necessary. 18. Contaminated coolant. a. Rusty coolant. a. Drain and flush cooling sys-
tem. Fill with correct coolant mixture.
b. Leaking marine gear oil cooler. b. Replace cooler. c. Oil leaks from oil cooler, head
gasket, head, and cylinder block.
c. Refer to Loss of lube oil. 19. Contaminated lube oil. a. Coolant in oil (internal leakage). a. Refer to Coolant loss.
b. Excessive oil sludge. b. Decrease oil change inter- vals. Ensure correct oil viscos- ity in use.
c. Fuel in oil (engine operating too cold).
c. Avoid excessive idling. Ensure engine comes up to temperature.
d. Fuel pump seal leaking. d. Replace pump. e. Injection nozzle needle valves
riot sealing.
e. Locate and replace nozzles, as necessary.
20. Fuel or oil leaking from exhaust manifold.
a. Intake air restriction. a. Replace filter element Avoid excessive idling.
b. Injection nozzle needle valve stuck open.
b. Locate and replace nozzles, as necessary.
S9233-C9-MMA-010
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
21. Compression knock. a. Air in fuel system. a. Bleed fuel system.
b. Poor quality fuel. b. Clean and flush fuel supply tanks. Refill with clean fuel oil. c. Engine overloaded. c. Reduce engine load and
speed.
d. Incorrect injection pump timing. d. Time injection pump. 22. Excessive fuel consump-
tion.
a. Overloading from faulty accesso- ries.
a. Repair/replace accessories, as necessary.
b. Poor quality fuel. b. Ensure proper grade of fuel is in use.
c. Inadequate intake air or exhaust restriction.
a. Refer to Excessive exhaust smoke.
d. Fuel pump timing. d. Time the pump. e. Worn or faulty nozzles. e. Replace nozzles. f. Valves not seating. f. Adjust valves.
23. Engine will not shut off. a. Fuel shutoff valve inoperative. a. Secure engine mechanically with lever on fuel pump. Replace sealing washer, piston, and spring.
b. Engine running on fumes drawn into the air intake.
b. Inspect air intake ducts for source of fumes, and correct. 24. Excessive vibration. a. Engine not running smoothly. a. Refer to Engine runs tough
or is misfiring.
b. Loose or broken engine mounts. b. Replace engine mounts. c. Faulty accessories. c. Replace vibrating compo-
nents. d. Worn or damaged alternator
bearing.
d. Replace the alternator. e. Flywheel housing misaligned. e. Realign flywheel housing. f. Loose or broken component in
engine.
f. Inspect internal engine com- ponents. Replace as necessary. g. Unbalanced shaft gear(s) or fly-
wheel.
g. Balance shaft or flywheel, as necessary.
25. Excessive engine noises. a. Drive belt squeal, insufficient tension, or excessive loading.
a. Ensure all belt drive compo- nents are properly adjusted. b. Intake air or exhaust leaks. b. Refer to Excessive exhaust
smoke.
c. Excessive valve lash. c. Ensure valves and pushrods are not bent and rocker arms are not excessively worn. Adjust valves.
d. Gear train noise. d. Inspect and measure gear train back lash. Replace gears, as necessary.
e. Internal engine components knocking.
e. Replace rod and main bear- ings.
Table 5-1. Troubleshooting Guide - Continued
Problem/Malfunction Probable Cause Corrective Action
26. Alternator not charging. a. Loose or corroded battery con- nections.
a. Clean and tighten battery connections
b. Alternator belt slipping. b. Replace belt tensioner or tighten belt, as necessary. c. Alternator pulley loose on shaft. c. Tighten pulley. d. Faulty alternator. d. Replace alternator.
5-3. TROUBLESHOOTING PROCEDURES.
The following procedures may be used to assist in troubleshooting the engine.
5-3.1 ENGINE WILL NOT CRANK.
a. Measure the voltage between the positive battery cable and ground. Note the voltage. b. Using a remote start switch, attempt to engage the starter while observing voltage. c. If the voltage reads less than 20 Vdc, charge the battery.
d. If the voltage drops rapidly more than 4.8 Vdc, replace the battery. e. If a low battery charge was found to be the problem, check the alternator.
f. Ensure proper battery cable connection. With the engine running, measure the voltage between the positive battery to the ground. Replace the alternator if the voltage is less than 24 Vdc.
5-3.2 ENGINE CRANKS BUT WILL NOT START (SMOKE FROM EXHAUST).
a. Remove the fuel shutdown valve.
b. Connect 24 Vdc to the terminal and ground the body. Observe plunger movement. If no movement, replace the valve.
c. Inspect fuel flow by removing the inlet line to the lift pump. d. Operate the fuel pump hand lever and check for suction.
e. If suction is detected, rotate the engine 90 degrees and repeat the check. f. If there is suction, check for an obstruction in the fuel supply line or tank.
5-3.3 ENGINE STARTS BUT WILL NOT KEEP RUNNING. Inspect for broken or bare wires. Those wires not accessible can be checked for continuity between the wire and ground.
5-3.4 ENGINE RUNNING HOT.
a. Check the temperature sensor for continuity. The sensor will have continuity only when coolant temperature is above 225°F.
S9233-C9-MMA-010
b. Check the thermostat for correct operation. With the thermostat suspended in water, it should begin to open when the heated water temperature reaches 181°F and be fully open at 203°F.
5-12
CHAPTER 6