Filling - MerCruiser 3.0 MPI Owner's Manual

5. With the engine at normal operating temperature, check that the coolant level in the
coolant recovery bottle is between the "ADD" and "FULL" marks.
6. Add the specified fluid as necessary.
Tube Ref No.

Filling

Using propylene glycol antifreeze in the closed cooling system can damage the cooling
system or the engine. Fill the closed cooling system with an ethylene glycol antifreeze
solution suitable to the lowest temperature to which the engine will be exposed.
Without sufficient cooling water, the engine, the water pump, and other components will
overheat and suffer damage. Provide a sufficient supply of water to the water inlets during
operation.
Air trapped in the closed cooling system can cause the engine to overheat, resulting in
engine damage. Minimize the possibility of trapping air when initially filling the closed
cooling system by positioning the boat so that the front of the engine is higher than the
rear of the engine.
NOTE: Add coolant only when the engine is at normal operating temperature.
1. Remove the fill cap from the coolant recovery bottle. Inspect the gasket and replace if
necessary.
IMPORTANT: Coolant flows at a high rate of speed in this closed cooling system. Higher
idle speeds can trap air in the system and make purge procedures more difficult. Operate
at idle when filling the system or purging air.
2. Fill to the full mark with the specified coolant.
Tube Ref No.
3. Check the antifreeze concentration for adequate freeze protection and correct if
necessary. Refer to the Specifications section.
90-899883272 MARCH 2008
Description
Extended Life Antifreeze/
122
Coolant
Description
Extended Life Antifreeze/
122
Coolant
6102
Where Used
Closed Cooling System
NOTICE
NOTICE
NOTICE
Where Used
Closed cooling system
Section 5 - Maintenance
Part No.
92-877770K1
Part No.
92-877770K1
Page 59