Inspection and Verification

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

1. Inspect the coolant color.
   NOTE: The cooling system is filled with Motorcraft® Specialty Green Engine Coolant or. Always fill the cooling system with the manufacturer's specified coolant. If a non-specified coolant has been used the cooling system must be chemically flushed. REFER to Cooling System Flushing . Failure to follow these instructions may damage the engine or cooling system.
   NOTE: The engine cooling system is filled with Motorcraft® Specialty Green Engine Coolant or. Mixing coolant types degrades the corrosion protection of the coolant. Do not mix coolant types. Failure to follow these instructions may damage the engine or cooling system.
   NOTE: Motorcraft® Specialty Green Engine Coolant is very sensitive to light. Do NOT allow this product to be exposed to ANY LIGHT for more than a day or two. Extended light exposure causes this product to degrade.
   NOTE: During normal vehicle operation, 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.
   • If Motorcraft® Specialty Green Engine Coolant or has a clear or pale color, this indicates higher water content than required. Test the engine coolant freezing point range with ROB75240. The freezing point should be in the range -50 C (-58 F) to -26.1 C (-15 F). If the vehicle is driven in cold climates less than -36.7 C (-34 F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 engine coolant to distilled water.
   • Discoloration of may indicate that incorrect coolant may have been added to the system. Use of incorrect (green or yellow) coolant degrades the corrosion protection of. Addition of Motorcraft® Specialty Green Engine Coolant may cause the color to appear to be a murky green-brown color. The addition of Motorcraft® Premium Gold Engine Coolant, however, may not change the color or appearance of the orange colored coolant. Detection of contamination with Motorcraft® Premium Gold Engine Coolant is determined by the presence of nitrite. If contamination with Motorcraft® Premium Gold Engine Coolant is suspected, test the coolant with 328-00001  . Follow the directions in the kit with regard to nitrite testing. If nitrite is present, flush the system and refill with the correct mixture of distilled water and. REFER to Cooling System Flushing .
   • A darker color 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 in the coolant sample, flush the system and refill with the correct mixture of distilled water and engine coolant. REFER to Cooling System Flushing .
   • 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 engine coolant. REFER to Cooling System Flushing .
   • An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. For information on engine diagnosis, REFER to SYMPTOM CHART: ENGINE PERFORMANCE . Flush the system and refill with the correct mixture of distilled water and engine coolant. REFER to Cooling System Flushing .
   • A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. REFER to Cooling System Pressure Test . If engine oil is suspected, the cause of the leak may be internal to the engine. For engine diagnosis, REFER to SYMPTOM CHART: ENGINE PERFORMANCE . Flush the system and refill with the correct mixture of distilled water and engine coolant. REFER to Cooling System Flushing .
2. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with ROB75240. The freezing point should be in the range of -50 C (-58 F) to -26.1 C (-15 F). If the vehicle is driven in cold climates less than -36.7 C (-34 F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 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.
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 undiluted engine coolant until the readings are within acceptable levels.
   • If the engine coolant tests strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.