Troubleshooting Chart - Yanmar 6LY3-STC Operation Manual

TROUBLESHOOTING CHART

Symptom
Alarm indicators and
alarm sound come on in
the display during oper-
ation.
• Lube oil low pressure
alarm indicator comes
on.
• Marine gear lube oil
pressure alarm indicator
comes on.
• Coolant high tempera-
ture alarm indicator
comes on.
Faulty Warning Devices
(1) When switch is turned ON:
• Alarm buzzer sounds.
• Alarm indicator comes
on.
(2) When the rocker switch returned to ON from START after engine starts:
• Buzzer keeps on sound-
ing.
• One of the alarm indica-
tors comes on.
• Battery low charge indi-
cator comes on during
operation.
White Exhaust Smoke at
Start
Black Smoke on Accel-
eration
6LY3 LDC Operation Manual
Probable Cause
Shift to low speed operation immediately, and check which indicator has come on in the display.
Stop the engine for inspection. If no abnormality is identified and there is no problem with oper-
ation, return to the port at lowest speed and request repairs.
• Engine lube oil level is low.
• Lube oil filter clogged.
• Marine gear lube oil is low.
• Coolant / fresh water in coolant
tank is low.
• Insufficient seawater causing tem-
perature to rise.
• Contamination inside cooling sys-
tem.
Do not operate the engine if alarm devices are not repaired. Serious accidents may result if
difficulties are not spotted due to faulty alarm lamps.
• Circuit broken.
Note: Alarm buzzer only sounds
when there is an abnormality.
• Circuit broken.
Note: Alarm indicator only comes on
when there is an abnormality.
• Sensor switches faulty
(if indicator comes on).
• Short-circuit
(if indicator does not come on).
• Sensor switches engine faulty.
• V-belt is loose or broken.
• Battery defective.
• Alternator power generation fail-
ure.
• DC-DC Converter failure.
• Poor fuel quality.
• Propeller too large.
• Hull bottom dirty.
© 2008 Yanmar Marine International
TROUBLESHOOTING
Measure
• Check lube oil level. Add
or replace.
• Replace lube oil filter.
Replace lube oil.
• Check the oil level and
supply.
• Check coolant level and
replenish.
• Check seawater system.
• See your authorized
Yanmar Marine dealer or
distributor.
• See your authorized
Yanmar Marine dealer or
distributors.
• See your authorized
Yanmar Marine dealer or
distributor.
• See your authorized
Yanmar Marine dealer or
distributor.
• See your authorized
Yanmar Marine dealer or
distributor.
• Replace V-belt; adjust
tension.
• Check battery fluid level,
specific gravity. Re-
place.
• See your authorized
Yanmar Marine dealer or
distributor.
• See your authorized
Yanmar Marine dealer or
distributor.
• Replace with fresh fuel.
• Replace with correct
size.
• Clean hull bottom.
Reference
Checking Engine Oil on
page 28.
Replace Engine Oil and
Engine Oil Filter on
page 52.
—
Check Diesel Fuel, En-
gine Oil and Engine
Coolant Levels on page
50.
—
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—
—
—
Adjust Alternator V-Belt
Tension on page 56.
Check the Battery on
page 55.
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