Cooling System

Cooling System Revisited

Checking your cars cooling system is one of the most important jobs in car maintenance. For Subarus it is especially important to use radiator coolant because of the all alloy engine so the correct ratio should be used and it needs to be changed regularly. Glycol based products are the best. Also check the condition of the radiator and heater hoses. Change when they appear to be soft and puffy and the radiator cap seal also needs to be checked. After time the standard hose clamps tend to cut into the hoses. It is best to replace the clamps with the after market worm drive types. Another good idea for all early L Series and MY models is to fit a coolant recovery tank, also the cap has to be replaced with a recovery type.

The operation of the electric fans is another important job because Subarus greatly rely on these fans for efficient cooling especially in slow 4WD work. The fans should switch on automatically once the engine reaches a certain operating temperature, set by the fans sensor switch. Check all the fans wiring and connectors. Another good idea is.to fit an over ride fan switch. It gives you more control over the fans operation. The simplest way to wire the switch up is to fit a piggy back connector to the wire going to the fan sensor switch on the radiator, run this wire back to the new switch in the dash then with another wire earth the switch. One thing to be aware of, for deeper water crossings that the fan or fans depending if an air conditioner is fitted, are off. The problem is when the cars hit the water with the fans running, the force of the water twists the fans mounting bracket which caused the blades to jam and then the fuse blows. If you are not aware of the problem, overheating will occur.

If you think your radiator may be blocked, most radiator services offer a service where they can flow test your radiator for the fee of around $10. They use a special machine that is able to test the flow rate against a specification chart. The radiator has to be removed from the car for the test. Also available are after market thermostats and electric fan sensor switches which start to operate at lower water temperatures. For an extra safety backup product to avoid cooling system problems there is a low water sensor, that has a dash mounted buzzer, that is sounded if the coolant drops below the sensor mounted in the top of the radiator. The cost is under $100 and they are available from most good accessory shops.

David Martin SC180

For more information on cooling system care see

Tech Talk Topic More Than Just A Coolant and Cooling System Care

Note: A concerned reader subsequently wrote to express a contrary opinion about using non-genuine coolants in Subarus. See Coolant Caution for details.