Inspection and Verification
Inspection and VerificationWARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap, wait until the engine is 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 sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth).
CAUTION: Check the coolant level, engine oil and transmission fluid, top off the coolant if needed. If there is engine coolant in the engine oil or transmission fluid, the cause must be corrected and oil/fluid changed or major component damage may occur.
1. Verify the customer's 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 an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the cause is not visually evident, verify the symptom and go to the Symptom Chart. Symptom Related Diagnostic Procedures
5. CAUTION: Some vehicle cooling systems are filled with Motorcraft Premium Gold Engine Coolant or equivalent (yellow color) meeting Ford specification WSS-M97B51-A1. Always fill the cooling system with the same coolant that is present in the system. Do not mix coolant types.
Inspect the coolant condition.
1. Inspect the coolant color.
^ If or equivalent meeting Motorcraft Premium Gold Engine Coolant Ford specification WSS-M97B51-A1 has a clear or pale yellow color, this indicates higher water content than required.
^ Dark brown can indicate unauthorized stop leak may have been used. Use Cooling System Stop Leak Pellets 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 engine coolant.
^ An iridescent sheen on top of the coolant can indicate a trace of oil is entering the system. For information on engine diagnosis, refer to Engine.
^ A milky brown color may indicate that engine oil is entering the cooling system. If engine oil is suspected, the cause of the leak may be internal to the engine. Refer to Engine.
2. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the battery and anti-freeze tester. The freezing point should be in the range -40°C to -20°C (-50°F to -10°F). If the vehicle is driven in cold climates less than -32°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection.
^ Maximum coolant concentration is 60 percent coolant/40 percent water.
^ Minimum coolant concentration is 40 percent coolant/60 percent water.
3. Adjust coolant range and level, if necessary.
^ If coolant is low, add specified coolant mixture only.
^ If the engine coolant tests too weak, 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 water until the readings are within acceptable levels.
6. If the concern remains after the inspection, determine the symptom(s) and GO to Symptom Chart. Symptom Related Diagnostic Procedures