Checking; Fault Cause; Coolant Temperature Too Low; Excessive Coolant Temperature - Volvo Penta D1-13 Workshop Manual

26-0 Cooling System, General
112

Checking

WARNING!
Do not open the coolant filler cap when the engine is
warm, except in emergencies, this could cause serious
personal injury. Steam or hot fluid could spray out.
Turn the filler cap to the first stop and allow any excess
pressure to hiss out before removing the cap com-
pletely. Top the coolant up as necessary. The level
must be between the MAX and MIN markings.

Fault cause

Coolant temperature too low

Low coolant temperature can be caused by:
• Faulty thermostat
Faulty temperature sensor or gauge
•
• Low engine loading

Excessive coolant temperature

Excessive coolant temperature (warning lamp lights
up) can be caused by:
• Blocked raw water inlet or raw water filter
• Defective impeller in the raw water pump
• Too low coolant level; air in the fresh water system
• Slipping or broken coolant pump vee belt
• Faulty thermostat, temperature sensor or gauge
• Blocked cooling system
• Incorrectly set injection advance in the injection
pump
• Filler cap gasket does not seal
Coolant losses
There are two types of coolant losses
Coolant losses during operation
•
• Coolant losses after stopping a hot engine
Coolant losses during operation can be due to a leak-
ing cooling system or air or combustion gases being
forced into the cooling system.
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