Cooling System Diagnosis; Engine Overheats; Loss Of Coolant; Engine Fails To Reach Normal Operating Temperature Or Cool Air From The Heater - Daewoo Nubira Owner's Manual

1D – 4IENGINE COOLING
Check for a loss of the coolant.
Check for a weak coolant solution.
Check the front of the radiator for any dirt, leaves, or in-
sects.
Check for leakage from the hoses, the coolant pump, the
heater, the thermostat housing, the radiator, the core
plugs, or the head gasket.
Check for a faulty thermostat.
Check for retarded ignition timing.
Check for an improperly operating electric cooling fan.
Check for radiator hoses that are plugged or rotted.
Check for a faulty water pump.
Check for a faulty surge tank cap.
Check for a cylinder head or an engine block that is
cracked or plugged.
Check for a leak in the radiator.
Check for a leak in the following locations:
S Surge tank.
S Hose.
Check for loose or damaged radiator hoses, heater hoses,
and connections.
Check for leaks in the coolant pump seal.
Check for leaks in the coolant pump gasket.
Check for an improper cylinder head torque.
Check for leaks in the following locations:
S Intake manifold.
S Cylinder head gasket.
S Cylinder block plug.
S Heater core.
S Radiator drain plug.
Engine Fails to Reach Normal Operating Temperature or Cool Air
Check to determine if the thermostat is stuck open or is the
wrong type of thermostat.
Check the coolant level to determine if it is below the MIN
mark on the surge tank.

COOLING SYSTEM DIAGNOSIS

Engine Overheats

Checks

Loss of Coolant

Checks
from the Heater
Checks
Add the coolant.
Confirm that the coolant solution is a 50/50 mixture of eth-
ylene glycol and water.
Clean the front of the radiator.
Replace any damaged components.
Replace a damaged thermostat.
Perform an PCM/ECM code diagnosis. Confirm the integ-
rity of the timing belt.
Replace the electric cooling fan.
Replace any damaged radiator hoses.
Replace the faulty water pump.
Replace the faulty surge tank cap.
Repair the damaged cylinder head or the damaged engine
block.
Replace the damaged radiator.
Replace the following parts, as needed:
S Surge tank.
S Hose
Reseat the hoses.
Replace the hoses or the clamps.
Replace the coolant pump seal.
Replace the coolant pump gasket.
Tighten the cylinder head bolts to specifications.
Replace the cylinder head gasket, if needed.
Repair or replace any components, as needed, to correct
the leak.
Install a new thermostat of the correct type and heat range.
Add sufficient coolant to raise the fluid to the specified
mark on the surge tank.
Action
Action
Action
DAEWOO V–121 BL4