Initial Inspection and Diagnostic Overview
Engine Cooling
Special Tool(s)
Inspection and Verification
WARNING: Never remove the pressure relief cap under any conditions while the engine is operating. Failure to follow these instructions can result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system, use extreme care when removing the pressure relief cap from a hot degas bottle. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly one turn (counterclockwise). Step back while the pressure is released from the cooling system. When certain all the pressure has been released, remove the pressure relief cap (still with a cloth).
CAUTION: Check the coolant level and engine oil, top off the coolant if needed. If there is engine coolant in the engine oil, the cause must be corrected and oil changed or major component damage can occur.
CAUTION: Vehicle cooling systems are filled with Motorcraft Premium Gold Engine Coolant VC-7-A (in California and Oregon VC-7-B, in Canada VC-7-C) or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color). Always fill the cooling system with the same coolant that is present in the system. Do not mix coolant types.
1. NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets VC-6, darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.
Verify the customer concern by operating the engine to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply.
Visual Inspection Chart
3. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary.
4. Inspect the coolant condition:
1. Inspect the coolant color.
^ If Motorcraft Premium Gold Engine Coolant VC-7-A (in California and Oregon VC-7-B, in Canada VC-7-C) or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color) has a clear or pale yellow color, this indicates higher water content than required.
^ Dark brown could indicate unauthorized stop leak may have been used. Use Motorcraft 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 water and Premium Gold Engine Coolant.
^ An iridescent sheen on the surface 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. If oil is suspected, the cause of the leak may be internal to the engine.
^ A milky brown color in the engine oil may indicate that coolant is entering the oil. If coolant is suspected, the cause of the leak may be internal to the engine.
2. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Battery/Antifreeze tester. The freezing point should be in the range of -45°C (-50°F) to 23°C (-10°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.
^ Maximum coolant concentration is 60/40.
^ Minimum coolant concentration is 40/60.
3. Adjust coolant range and level if necessary:
^ If the coolant is low, add specified coolant mixture only.
^ If the coolant tests weak, add straight engine coolant until the readings are within acceptable levels.
^ If the coolant tests strong, remove some of the engine coolant and add water until the readings are within acceptable levels.
5. If the concern remains after the inspection, determine the symptom(s). GO to Symptom Chart. Symptom Related Diagnostic Procedures
6. Verify the cooling system is correctly filled and bled.