GM Service Manual Online
For 1990-2009 cars only

Checks

Actions

A loss of coolant

Add coolant.

A weak coolant solution

Confirm that the coolant solution is a 50/50 mixture of ethylene glycol and water.

Any dirt, any leaves, or any insects in front of the radiator

Clean the front of the radiator.

Leakage from the following components:

    • The hoses
    • The coolant pump
    • The heater
    • The thermostat housing
    • The radiator
    • The core plugs
    • The head gasket

Replace any damaged components.

A faulty thermostat

Replace a damaged thermostat.

Retarded ignition timing

Perform an ECM code diagnosis. Confirm the integrity of the timing belt.

An improperly operating electric cooling fan

Replace the electric cooling fan.

Plugged or rotted radiator hoses

Replace any damaged radiator hoses.

A faulty water pump

Replace a faulty water pump.

A faulty surge tank cap

Replace a faulty surge tank cap.

A cracked or plugged cylinder head or engine block

Repair the damaged cylinder head or the damaged engine block.