Section 7 - Troubleshooting
90-8M0053263 NOVEMBER 2010
Page 79
Possible Cause
Remedy
Running rich.
Have authorized Mercury MerCruiser dealer check and repair.
Excessive Engine Temperature
Possible Cause
Remedy
Water inlet or seacock closed.
Open.
Drive belt loose or in poor condition.
Replace or adjust belt.
Seawater pickups or sea strainer obstructed.
Remove obstruction.
Faulty thermostat.
Replace.
Coolant level (if equipped) low in closed cooling section.
Check for cause of low coolant level and repair. Fill system with
proper coolant solution.
Heat Exchanger or Fluid Cooler plugged with foreign material Clean Heat Exchanger, Engine Oil Cooler, and Transmission
Oil Cooler (if equipped).
Loss of pressure in closed cooling section.
Check for leaks. Clean, inspect and test pressure cap.
Faulty seawater pickup pump.
Repair.
Seawater discharge restricted or plugged.
Clean exhaust elbows.
Insufficient Engine Temperature
Possible Cause
Remedy
Faulty thermostat.
Replace.
Low Engine Oil Pressure
Possible Cause
Remedy
Insufficient oil in crankcase.
Check and add oil.
Excessive oil in crankcase (causing it to
become aerated).
Check and remove required amount of oil. Check for cause of excessive oil
(improper filling).
Diluted or improper viscosity oil.
Change oil and oil filter, using correct grade and viscosity oil. Determine cause
for dilution (excessive idling).
Battery Will Not Recharge
Possible Cause
Remedy
Excessive current draw from battery.
Turn off non‑essential accessories.
Alternator drive belt loose or in poor condition.
Replace and/or adjust.
Unacceptable battery condition.
Test battery, replace if necessary.
Loose or dirty electrical connections or damaged
wiring.
Check all associated electrical connections and wires (especially
battery cables). Clean and tighten faulty connections. Repair or replace
damaged wiring.
Faulty alternator
Test alternator output, replace if necessary.
