Initial Inspection and Diagnostic Overview

Special Tools:

Inspection and Verification

WARNING: Never remove the pressure relief cap under any conditions while the engine is operating or hot. Failure to follow these instructions could result in personal injury or damage to the cooling system or engine. To avoid having scalding hot coolant or steam blow out of the cooling system, use extreme care when removing the pressure relief cap. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are certain all the pressure has been released, (with a cloth) turn and remove the pressure relief cap. Failure to follow these instructions may result in personal injury.

CAUTION: The engine cooling system is filled with Motorcraft Premium Gold Engine Coolant with Bittering Agent (US only) VC-7-B (US); CVC-7-A (Canada); or equivalent (yellow color) meeting Ford specification WSS-M97B51-A1. Do not mix coolant types.

NOTE: Vehicles equipped with a degas bottle system have the pressure relief cap on the degas bottle and no radiator cap. Vehicles equipped with a coolant expansion tank system have the pressure relief cap on the radiator.

1. Verify the customer concern.
2. Visually check the engine coolant level at the degas bottle or coolant expansion tank when the system is cold.
3. Make sure the pressure relief cap is installed correctly.
4. Record any cooling system diagnostic trouble codes (DTCs) retrieved.

5. NOTE: Take note of any coolant odor or steam coming from cooling system components.

If the system coolant is filled correctly and no DTCs associated with fail-safe cooling are retrieved, verify the customer's concern by operating the engine to duplicate the condition.

6. NOTE: Refer to the coolant flow diagram in the Description and Operation.

Inspect to determine if any of the following mechanical or electrical concerns apply.

Visual Inspection Chart

Visual Inspection Chart (Part 1):

Visual Inspection Chart (Part 2):

7. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary. Test the system for normal operation.
8. Inspect the coolant condition.
1 Inspect the coolant color.
^ If Motorcraft Premium Gold Engine Coolant with Bittering Agent (US only) VC-7-B (US); CVC-7-A (Canada); or equivalent (yellow color) meeting Ford specification WSS-M97B51-A1 has a clear or pale yellow color, this indicates higher water content than required.

^ NOTE: If Cooling System Stop Leak Pellets VC-6 or equivalent meeting Ford specification WSS-M99B37-B6 are used, darkening of the Motorcraft Premium Coolant from yellow to golden tan will occur.

Dark brown could indicate unauthorized stop leak may have been used. Use Cooling System Stop Leak Pellets VC-6 or equivalent meeting Ford specification WSS-M99B37-B6.
^ 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 Premium Gold Engine Coolant.
^ An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system.
^ A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. Refer to component tests. If engine oil is suspected, the cause of the leak may be internal to the engine.
^ A red, orange or light green colored sheen on top of the coolant may indicate that transmission fluid is entering the cooling system. The cause may be a leaky radiator. Pressure test the cooling system. Refer to the component tests.

2 If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Battery/Anti-Freeze Tester. The freezing point should be in the range -45°C to -23°C (-50°F to -10°F). If the vehicle is driven in cold climates less than -36°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 ethylene glycol to distilled water.
^ Maximum coolant concentration is 60/40 for cold weather areas.
^ Minimum coolant concentration is 40/60 for warm weather areas.

3 Adjust coolant range and level if necessary:
^ If coolant is low, add specified coolant mixture only.
^ If the engine coolant tests too weak, remove some of the engine coolant and add straight engine coolant until the readings are within acceptable levels.
^ If the engine coolant tests strong, remove some of the engine coolant and add straight distilled water until the readings are within acceptable levels.

9. If the concern remains after the inspection, determine the symptom(s). GO to Symptom Chart. Symptom Related Diagnostic Procedures