Coolant Inspection

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

For information on Ford Color Coded Illustrations refer to OEM COLOR CODING .

Special Tool(s)

Courtesy of FORD MOTOR COMPANY

Coolant/Battery Refractometer ROB75240 or equivalent

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: 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, coolant can change color. 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.

NOTE: Take note of any coolant odor coming from cooling system.

Visually check the engine coolant level at the degas bottle when the system is cold.
Make sure the pressure relief cap is installed correctly.
Inspect the coolant condition.
1. Inspect the coolant color.
  - 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, flush the system and refill with the correct mixture of distilled water and the appropriate concentrated antifreeze/coolant. For additional information, refer to: Specifications . For additional information, refer to: Engine Cooling System Flushing - With Oil or Transmission Fluid Contamination . For additional information, refer to: Engine Cooling System Flushing - Without Oil or Transmission Fluid Contamination .
  - 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 the appropriate concentrated antifreeze/coolant. For additional information, refer to: Specifications . For additional information, refer to: Engine Cooling System Flushing - With Oil or Transmission Fluid Contamination . For additional information, refer to: Engine Cooling System Flushing - Without Oil or Transmission Fluid Contamination .
  - An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. For engine diagnosis, For additional information, refer to: Engine - Diesel . Flush the system and refill with the correct mixture of distilled water and the appropriate concentrated antifreeze/coolant.For additional information, refer to: Specifications . For additional information, refer to: Engine Cooling System Flushing - With Oil or Transmission Fluid Contamination . For additional information, refer to: Engine Cooling System Flushing - Without Oil or Transmission Fluid Contamination .
  - A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. If engine oil is suspected, the cause of the leak may be internal to the engine. For engine diagnosis, For additional information, refer to: Engine - Diesel . Flush the system and refill with the correct mixture of distilled water and the appropriate concentrated antifreeze/coolant.For additional information, refer to: Specifications . For additional information, refer to: Engine Cooling System Flushing - With Oil or Transmission Fluid Contamination . For additional information, refer to: Engine Cooling System Flushing - Without Oil or Transmission Fluid Contamination .
2. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Coolant/Battery Refractometer. Maintain the coolant concentration.For additional information, refer to: Specifications .
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 the appropriate concentrated antifreeze/coolant until the readings are within acceptable levels.For additional information, refer to: Specifications .
  - If the engine coolant tests strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.