Insufficient Engine Temperature; High Engine Temperature - Mercury 565 Manual

Insufficient Engine Temperature

Possible Cause
Faulty water thermostat.
Faulty gauge or sender.
Faulty oil thermostat.

High Engine Temperature

Possible Cause
Seacock closed.
Serpentine belt loose or in poor condition.
Insufficient coolant in closed cooling
system.
Recirculating pump defective.
Seawater pickups obstructed.
Faulty thermostat.
Oil cooler cores plugged with foreign
material.
Faulty seawater pickup pump.
Seawater discharge restricted or plugged.
Faulty gauges or senders.
Aerated water supply to water pick‑up.
eng
TROUBLESHOOTING
Replace water thermostat.
Test with shop gauge; test sender.
Replace.
Remedy
Open.
Replace or adjust belt.
Add coolant and check for leaks.
Replace.
Inspect.
Replace.
Clean cooler cores.
Repair.
Clean exhaust elbows.
Test with shop gauges; test
senders.
Place water pick‑up in a
non‑aerated water supply.
95
Remedy