Excessive Engine Temperature; Insufficient Engine Temperature; Low Engine Oil Pressure; Battery Will Not Come Up On Charge - Mercury Inboard 5.7L Manual

Boat bottom fouled or damaged.
Ignition problem.
Engine overheating.
Running rich.

Excessive Engine Temperature

Water inlet or seacock closed.
Drive belt loose or in poor condition.
Seawater pickups or sea strainer obstructed.
Faulty thermostat.
Coolant level (if equipped) low in closed cooling
section.
Heat Exchanger or Fluid Cooler plugged with foreign
material
Loss of pressure in closed cooling section.
Faulty seawater pickup pump.
Seawater discharge restricted or plugged.

Insufficient Engine Temperature

Faulty thermostat.

Low Engine Oil Pressure

Insufficient oil in crankcase.
Excessive oil in crankcase (causing it to become
aerated).
Diluted or improper viscosity oil.

Battery Will Not Come Up On Charge

Excessive current draw from battery.
Alternator drive belt loose or in poor condition.
Unacceptable battery condition.
Loose or dirty electrical connections or damaged
wiring.
Faulty alternator
90-860174050 JUNE 2005
Possible Cause
Possible Cause
Possible Cause
Possible Cause
Possible Cause
Remedy
Clean or repair as necessary.
See Engine Runs Rough, Misses or Backfires.
See Excessive Engine Temperature.
Have authorized Mercury MerCruiser dealer check and
repair.
Open.
Replace or adjust belt.
Remove obstruction.
Replace.
Check for cause of low coolant level and repair. Fill
system with proper coolant solution.
Clean Heat Exchanger, Engine Oil Cooler, and
Transmission Oil Cooler (if equipped).
Check for leaks. Clean, inspect and test pressure cap.
Repair.
Clean exhaust elbows.
Replace.
Check and add oil.
Check and remove required amount of oil. Check for
cause of excessive oil (improper filling).
Change oil and oil filter, using correct grade and
viscosity oil. Determine cause for dilution (excessive
idling).
Turn off non‑essential accessories.
Replace and/or adjust.
Test battery, replace if necessary.
Check all associated electrical connections and wires
(especially battery cables). Clean and tighten faulty
connections. Repair or replace damaged wiring.
Test alternator output, replace if necessary.
Troubleshooting
Remedy
Remedy
Remedy
Remedy
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