Cooling System Inspection - 2.3L

WARNING: This page is about a different car, the 2008 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

Allow the engine to cool and remove the coolant recovery reservoir cap.
Inspect the coolant condition:
- Vehicles with Mazda Premium Gold Engine Coolant VC-7-A (in Oregon VC-7-B), have a clear or pale yellow color, this indicates higher water content than required.
  NOTE:
  - The addition of stop leak pellets, darkens Mazda Premium Gold Engine Coolant VC-7-A from yellow to golden tan. Dark brown could indicate unauthorized stop leak may have been used. Use Cooling System Stop Leak Pellets VC-6 or equivalent.
- 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 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 either engine oil or transmission 'fluid is entering the cooling system. If transmission fluid is suspected, the cause may be a leaky radiator; pressure test the cooling system. If engine oil is suspected, the cause of the leak may be internal to the engine.
- If transmission fluid is contaminated with engine coolant, the cause may be a leaky radiator; pressure test the system.
If the engine coolant appearance is acceptable, test the engine coolant freezing point range with a suitable coolant tester. The freezing point should be in the range -46°C to -23°C (-51 °F to -9°F). If the vehicle is driven in cold climates less than -37°C (-35°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.
Adjust coolant range and level if necessary:
- If coolant is low, add specified coolant mixture only.
- If the engine coolant tests 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.