303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma 2014 Fiesta
Diagnosis and Testing Procedure revision date: 05/15/2013

Engine Cooling


Special Tool(s)
3-Way HD Antifreeze Coolant Test Kit
328-2050-62291 or equivalent
Coolant/Battery Refractometer
300-ROB75240 or equivalent
Pressure Tester
STN12270 or equivalent
UView Combustion Leak Tester
UVU560000-R



  Material : Motorcraft® Orange Antifreeze/Coolant Concentrated / VC-3-B (WSS-M97B44-D)
  Material : Motorcraft® Orange Antifreeze/Coolant Prediluted / VC-3DIL-B (WSS-M97B44-D2)


DTC Chart

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).



  PCM DTC Chart


DTC Description Action
P0125 Insufficient Coolant Temp For Closed Loop Fuel Control   GO to Pinpoint Test C
P0128 Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)   GO to Pinpoint Test C
P0217 Engine Coolant Overtemperature Condition   GO to Pinpoint Test B
P0480 Fan 1 Control Circuit   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
P0481 Fan 2 Control Circuit   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
P0691 Fan 1 Control Circuit Low   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
P0692 Fan 1 Control Circuit High   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
P0693 Fan 2 Control Circuit Low   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
P0694 Fan 2 Control Circuit High   Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
All Other PCM Diagnostic Trouble Codes (DTCs)    
REFER to: Electronic Engine Controls (303-14A Electronic Engine Controls - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).


Inspection and Verification

NOTICE: The engine cooling system is filled with Motorcraft® Orange Antifreeze/Coolant. Always fill the cooling system with the manufacturer's specified coolant. Chemically flush the cooling system if a non-specified coolant has been used. Failure to follow these instructions may damage the engine or cooling system.

NOTE: During normal vehicle operation, Motorcraft® Orange Antifreeze/Coolant may change color from orange to pink or light red. As long as the engine coolant is clear and uncontaminated, this color change does not indicate the engine coolant has degraded nor does it require the engine coolant to be drained, the system to be flushed, or the engine coolant to be replaced.

  1. Verify the customer concern.
  1. Visually check the engine coolant level at the degas bottle when the system is cold.
  1. Make sure the pressure relief cap is installed correctly.
  1. Record any cooling system Diagnostic Trouble Codes (DTCs) retrieved. Refer to the PCM DTC chart in this section for DTC descriptions.
  1. NOTE: Take note of any coolant odor or steam coming from cooling system components.

    If the system coolant is filled correctly and no Diagnostic Trouble Codes (DTCs) associated with fail-safe cooling are retrieved, verify the customer concern by operating the engine to duplicate the condition.
  1. Visually inspect for obvious signs of any mechanical or electrical damage.


  Visual Inspection Chart


Mechanical Electrical
  • Leaks or weeps at:
    • Hoses
    • Tubes
    • Hose clamps
    • Engine gaskets (may leak internally or externally)
    • Thermostat housing
    • Radiator
    • Pressure relief cap
    • Coolant pump
    • Engine oil cooler (may leak internally or externally) (if equipped)
    • Heater core (wet floor or coolant odor in vehicle)
    • Degas bottle
    • Cylinder block core plugs
    • Cylinder head core plugs
    • Block heater (if equipped)
  • Cracked or damaged:
    • Hoses
    • Tubes
    • Hose clamps
    • Thermostat housing
    • Radiator
    • Pressure relief cap
    • Cooling fan
    • Coolant pump
    • Engine oil cooler (if equipped)
    • Degas bottle
    • Cylinder block core plugs
    • Cylinder head core plugs
    • Block heater (if equipped)
  • Restricted airflow through the A/C condenser/radiator
  • Excessive white or light gray exhaust smoke (may have burnt coolant odor)
  • Coolant in engine oil
  • Engine oil in coolant
  • Inoperative or damaged:
    • Electric cooling fan
    • Wiring, connectors, relays or modules
    • ECT sensor
    • Vehicle Speed Sensor (VSS)


  1. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary.
  1. Inspect the coolant condition.
    1. Inspect the coolant color.
      • Discoloration may indicate that incorrect coolant may have been added to the system. Use of incorrect (green or yellow in color) coolant degrades the corrosion protection of Motorcraft® Orange Antifreeze/Coolant. Addition of Motorcraft® Specialty Green Engine Coolant may cause the color to appear to be a murky green-brown color. The addition of Motorcraft® Gold Antifreeze/Coolant, however, may not change the color or appearance of the orange colored coolant. Detection of contamination with Motorcraft® Gold Antifreeze/Coolant is determined by the presence of nitrite. If contamination with Motorcraft® Gold Antifreeze/Coolant is suspected, test the coolant with the 3-Way HD Antifreeze Coolant Test Kit. Follow the nitrite testing directions in the kit to determine if nitrite is present in the system. If nitrite is present, flush the system and refill with the correct mixture of distilled water and Motorcraft® Orange Antifreeze/Coolant Concentrated.
        REFER to: Cooling System Draining and Vacuum Filling (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, General Procedures).

      • A darker orange with the presence of debris could indicate a commercially available stop leak may have been used and could result in loss of coolant flow to critical parts of the engine. If sediment is present, flush the system and refill with the correct mixture of distilled water and Motorcraft® Orange Antifreeze/Coolant Concentrated.
        REFER to: Cooling System Draining and Vacuum Filling (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, General Procedures).

      • A light or reddish brown color indicates that rust may be present in the cooling system. Flush the system and refill with the correct mixture of distilled water and Motorcraft® Orange Antifreeze/Coolant Concentrated.
        REFER to: Cooling System Draining and Vacuum Filling (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, General Procedures).

      • An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. For engine diagnosis,
        REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
        Flush the system and refill with the correct mixture of distilled water and Motorcraft® Orange Antifreeze/Coolant Concentrated. REFER to: Cooling System Draining and Vacuum Filling (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, General Procedures).

      • A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. Refer to component tests in this section. If engine oil is suspected, the cause of the leak may be internal to the engine. For engine diagnosis,
        REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
        Flush the system and refill with the correct mixture of distilled water and Motorcraft® Orange Antifreeze/Coolant Concentrated. REFER to: Cooling System Draining and Vacuum Filling (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, General Procedures).

    1. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Coolant/Battery Refractometer. Maintain the coolant concentration within 48% to 50%, which equates to a freeze point between -34°C and -37°C (-30°F and -34°F). If the vehicle is driven in cold climates less than -37°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 48/52 to 50/50 (freeze protection -34°C to -37°C [-30°F to -34°F]) engine coolant to distilled water.
      • Maximum coolant concentration is 60/40 for cold weather areas.
      • Minimum coolant concentration is 40/60 for warm weather areas.
    1. Adjust coolant concentration and level if necessary:
      • If coolant concentration is acceptable, but level is low, add specified coolant mixture only.
      • If the engine coolant concentration tests too weak, remove some of the engine coolant and add Motorcraft® Orange Antifreeze/Coolant Concentrated until the readings are within acceptable levels.
      • If the engine coolant concentration tests too strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.
  1. If an obvious cause for an observed or reported concern is found, correct the cause and test the system for normal operation before proceeding to the next step.

Symptom Chart

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).




Condition Possible Sources Actions
Loss of coolant Refer to the Pinpoint Test   GO to Pinpoint Test A
The engine overheats. Refer to the Pinpoint Test   GO to Pinpoint Test B
The engine does not reach normal operating temperature. Refer to the Pinpoint Test   GO to Pinpoint Test C
The block heater does not operate correctly.
  • Block heater power cable
  • Block heater
  • CHECK continuity in all 3 power cable circuits. If any circuit measures more than 5 ohms, INSTALL a new power cable.
  • CHECK the resistance of the block heater. If the resistance does not measure between 12.5 and 17 ohms, INSTALL a new block heater.
The electric cooling fan is inoperative in one or more speeds or does not operate correctly.
  • Wiring
  • Relays
  • Fuses
  • Cooling fan motor
  • Cooling fan resistor
  Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
The electric cooling fan stays on all the time.
  • Wiring
  • Relays
  Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual.
Noisy electric cooling fan operation.
  • Foreign material contamination
  • Fan motor
  • REMOVE the foreign material from the cooling fan and shroud. TEST the system for normal operation. If still noisy, INSTALL a new cooling fan assembly.
  • Fan blade detached from fan motor
  • INSTALL a new cooling fan assembly.


Pinpoint Tests

Loss of Coolant

Normal operation and Fault Conditions

The engine cooling system is a closed system providing for coolant expansion and contraction as well as changes in pressure as coolant warms and cools with engine operation. Various gaskets, seals, hoses and clamps contain coolant within the cooling system and keep other fluids and contaminants from entering the cooling system.

Possible Sources


PINPOINT TEST A : PINPOINT TEST
WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.
A1   CARRY OUT INSPECTION AND VERIFICATION
  • Carry out Inspection and Verification.

Are any concerns present?

Yes REPAIR as needed.
No GO to A2


A2   CHECK THE ENGINE COOLANT LEVEL AND PRESSURE TEST THE ENGINE COOLING SYSTEM

NOTE: Allow the engine to cool before checking the engine coolant level.

  • Ignition OFF
  • Visually inspect the engine coolant level at the degas bottle and adjust as necessary. Pressure test the engine cooling system. Refer to Component Tests, Cooling System Pressure Test in this section.

Does the engine cooling system leak externally?

Yes REPAIR or INSTALL new components.
No GO to A3


A3   CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK
  • Inspect the engine coolant in the degas bottle for signs of engine oil.

Is engine oil evident in the engine coolant?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No GO to A4


A4   CHECK THE ENGINE OIL FOR COOLANT
  • Remove the oil level indicator from the engine.

Is coolant evident in the oil?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No GO to A5


A5   CHECK THE COOLING SYSTEM FOR COMBUSTION GASES

NOTE: Use UView Combustion Leak Tester part number UVU560000-R or equivalent.

  • Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases.

Are combustion gases present?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No The cooling system is operational



The Engine Overheats

Normal operation and Fault Conditions

The engine cooling system maintains the engine temperature during operation. Correct coolant flow through the engine, radiator and remainder of cooling system passages and components is essential to maintaining a correct engine temperature.

Engine coolant flows primarily from the engine to the radiator circuit and back to the coolant pump. Coolant is sent from the coolant pump through the engine block and cylinder heads. A separate circuit from the engine also feeds the heater core with coolant. The coolant pump circulates the coolant. The coolant thermostat is a control valve actuated by coolant temperature. When the thermostat is closed, coolant flow bypasses the radiator circuit and returns to the coolant pump. When the thermostat is opened, coolant flows through the radiator circuit to transfer engine-generated heat to the outside air.

Engine overheating generally occurs when there is a disruption in the ability to control either coolant flow at the correct rate, the inability to transfer heat from the engine through the coolant (including low coolant) or an inability to transfer engine-generated heat to the outside air through the radiator.

Possible Sources



  Diagnostic Trouble Code (DTC) Fault Trigger Conditions


DTC Description Fault Trigger Conditions
P0217 Engine Coolant Overtemperature Condition Sets in the PCM when an engine overheat condition was sensed by the ECT sensor.



PINPOINT TEST B : PINPOINT TEST
B1   CARRY OUT INSPECTION AND VERIFICATION
  • Carry out the Inspection and Verification procedure in this section.

Are any concerns present?

Yes REPAIR as needed.
No GO to B2


B2   CHECK FOR AN AIRFLOW OBSTRUCTION
  • Check the radiator or A/C condenser for an external obstruction such as leaves or cardboard.

Is an obstruction present?

Yes REMOVE the obstruction.
No GO to B3


B3   CHECK THE ENGINE COOLANT LEVEL AND PRESSURE TEST THE COOLING SYSTEM
  • Ignition OFF.
  • Visually check the engine coolant level in the coolant expansion tank and adjust as necessary. Pressure test the cooling system.

Does the engine cooling system leak externally?

Yes REPAIR or INSTALL new components.
No GO to B4


B4   CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK
  • Inspect the engine coolant in the coolant expansion tank for signs of engine oil.

Is engine oil evident in the coolant?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No GO to B5


B5   CHECK THE ENGINE OIL FOR COOLANT
  • Remove the oil level indicator from the engine.

Is coolant evident in the oil?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No GO to B6


B6   CHECK THE COOLING SYSTEM FOR COMBUSTION GASES

NOTE: Use UView Combustion Leak Tester part number UVU560000-R or equivalent.

  • Using a cooling system combustion gas leak tester, following the instructions supplied with the tester, check the coolant for combustion gases.

Are combustion gases present?

Yes
REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).
No GO to B7


B7   CHECK COOLANT CONDITION
  • Check the coolant for dirt, rust or contamination and check the coolant concentration.

Is the coolant condition OK?

Yes GO to B8
No FLUSH the engine cooling system.


B8   CHECK THE ELECTRIC COOLING FAN OPERATION
  • Start the engine.
  • Place the climate control function selector in the MAX A/C position and the blower motor switch in the HI position.



Yes GO to B9
No DIAGNOSE the electric cooling fan operation. Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual. Section 3 Symptom Charts.


B9   CHECK THE COOLANT PUMP OPERATION
  • Start the engine.
  • Allow the engine to run for 30 minutes. Place the climate control function selector in the MAX HEAT position. Feel the heater outlet hose.

Is the heater outlet hose hot?

Yes GO to B10
No INSTALL a new coolant pump.
REFER to: Coolant Pump (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).


B10   CHECK THE THERMOSTAT OPERATION
  • Start the engine.
  • Allow the engine to run for 30 minutes. Place the climate control function selector in the MAX HEAT position. Feel the lower radiator hose.

Is the lower radiator hose hot?

Yes CHECK the temperature gauge operation.
REFER to: Instrument Panel Cluster (IPC) and Panel Illumination (413-00 Instrument Panel Cluster (IPC) and Panel Illumination, Diagnosis and Testing).
No GO to B11


B11   VISUALLY INSPECT THE THERMOSTAT
  • Carry out the Thermostat Visual Inspection in the Component Tests portion of this section.

Is the thermostat damaged?

Yes INSTALL a new thermostat.
REFER to: Thermostat (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).
No INSTALL a new thermostat.
REFER to: Thermostat (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).
If the engine still overheats, INSTALL a new radiator. REFER to: Radiator (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).



The Engine Does Not Reach Normal Operating Temperature


Refer to Wiring Diagrams Section - for schematic and connector information.

Normal operation and Fault Conditions

The engine cooling system maintains engine temperature during operation. Correct coolant flow through the engine, radiator and remainder of cooling system passages and components is essential to maintaining a correct engine temperature.

Engine coolant flows primarily from the engine to the radiator circuit and back to the coolant pump. Coolant is sent from the coolant pump through the engine block and cylinder heads. A separate circuit from the engine also feeds the heater core with coolant. The coolant pump circulates the coolant. The coolant thermostat is a control valve actuated by coolant temperature. When the thermostat is closed, coolant flow bypasses the radiator circuit and returns to the coolant pump. When the thermostat is opened, coolant flows through the radiator circuit in order to transfer engine generated heat to the outside air.

Concerns of engine inability to reach normal operating temperature typically occur when the rate of coolant flow through some coolant circuits (radiator, heater core) is more than expected given the conditions. Heat is not allowed to build in the engine because a heat exchanger is removing too much heat, including the radiator, heater core and oil cooler. In addition, perceived concerns that the engine does not reach normal operating temperature can be related to a low coolant level or trapped air which does not allow for hot coolant to be available at the heater core, an inoperative climate control system, or for concerns perceived or related to an incorrect engine temperature gauge indication.

Possible Sources



  Diagnostic Trouble Code (DTC) Fault Trigger Conditions


DTC Description Fault Trigger Conditions
P0125 Insufficient Coolant Temp for Closed Loop Fuel Control Sets in the PCM when the ECT sensor has not achieved the required temperature level to enter closed loop operating conditions within a specified amount of time after starting the engine.
P0128 Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature) Sets in the PCM when the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine.



PINPOINT TEST C : PINPOINT TEST
WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.
C1   CARRY OUT INSPECTION AND VERIFICATION
  • Carry out the Inspection and Verification procedure in this section.

Were any concerns found?

Yes REPAIR as needed.
No GO to C2


C2   CHECK FOR DTC P0125 OR P0128
  • Using a scan tool, perform the PCM self-test.

Is DTC P0125 or P0128 present?

Yes GO to C3
No The cooling system is operational. If an inoperative temperature gauge is suspected, CHECK the temperature gauge operation.
REFER to: Instrument Panel Cluster (IPC) and Panel Illumination (413-00 Instrument Panel Cluster (IPC) and Panel Illumination, Diagnosis and Testing).
If an inoperative climate control system is suspected, CHECK the climate control system operation. For Electonic Automatic Temperature Control (EATC)REFER to: Climate Control System - Vehicles With: Electronic Automatic Temperature Control (EATC) (412-00 Climate Control System - General Information, Diagnosis and Testing).
For Electronic Manual Temperature control (EMTC) REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) (412-00 Climate Control System - General Information, Diagnosis and Testing).
If any other Diagnostic Trouble Codes (DTCs) are retrieved, REFER to: Electronic Engine Controls (303-14A Electronic Engine Controls - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).


C3   CHECK THE ECT (ENGINE COOLANT TEMPERATURE) SENSOR OPERATION
  • Using a scan tool, view PCM PIDs.
  • Monitor the ECT temperature PID.
  • Using an Infrared temperature gun measure and record the temperature of the coolant outlet housing at the rear of the cylinder head near the ECT sensor.

Is the temperature reading similar to the ECT PID value?

Yes INSTALL a new thermostat.
REFER to: Thermostat (303-03A Engine Cooling - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).
No INSTALL a new ECT sensor.
REFER to: Engine Coolant Temperature (ECT) Sensor (303-14A Electronic Engine Controls - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Removal and Installation).



Component Tests

Cooling System Pressure Test

WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.

NOTE: Vehicles have a pressure relief cap on the degas bottle and no radiator cap.

  1. Turn the engine OFF.
  1. Check the engine coolant level and adjust as necessary.
  1. Remove the degas bottle cap. Inspect the degas bottle cap and degas bottle for any issues that would cause improper sealing, such as for cross-threading, burrs, damaged o-ring, etc. If any issues are found, INSTALL a new cap and/or degas bottle.
  1. Attach the Pressure Tester and adaptor (Snap-On TA53 or equivalent), to the degas bottle cap. The cap must hold pressure of 145 kPa +/- 21 kPa (21 PSI +/- 3 PSI). If any issues are found, INSTALL a new cap.
  1. Attach the Pressure Tester and adaptor (Snap-On TA52, AST ASSFZ-47, Redline RDL95-0750 or equivalent) to the degas bottle.

NOTICE: Do not pressurize the cooling system beyond the maximum pressure listed in the specifications table in this section, or cooling system components can be damaged.

NOTE: If the plunger of the pressure tester is pressed too fast, an erroneous pressure reading will result.

  1. To pressurize the engine cooling system, slowly press the plunger of the pressure test pump and increase the pressure to between 124 - 138 kPa (18 - 20 PSI). Observe the gauge reading for approximately 2 minutes. Pressure should not drop during this time. If the pressure drops within this time, inspect for leaks and repair as necessary.
  1. If no leaks are found and the pressure drops, the leak may be internal to the engine. Inspect the coolant for engine oil and the engine oil for coolant.
    REFER to: Engine (303-01A Engine - 1.6L Duratec-16V Ti-VCT (88kW/120PS) - Sigma, Diagnosis and Testing).

  1. If the pressure does not drop remove the cooling system Pressure Tester and adaptor from degas bottle.
  1. Install the degas bottle cap until it contacts the hard stop.

Thermostat

Install a new thermostat only after at least one of the following tests and checks have been carried out:

Thermostat Visual Inspection

  1. Remove the thermostat.
  1. Examine the thermostat for signs of damage including:
  1. NOTE: If no damage is found during the inspection, do not attempt to open the thermostat using hot water or other heat sources. This method is not an accurate means to test the function of the thermostat and may damage the thermostat.

    If damage is found during the inspection, remove any foreign material or broken pieces and install a new thermostat.

Radiator Leak Test, Removed From Vehicle

NOTICE: Never leak test an aluminum radiator in the same water that copper/brass radiators are tested in. Flux and caustic cleaners may be present in the cleaning tank and they will damage aluminum radiators.

NOTE: Clean the radiator before leak testing to avoid contamination of tank.

  1. Leak test the radiator in clean water with air pressurized to the maximum pressure listed in the Specifications table.