How often should I change the coolant on my Subaru Forester?

The recommended coolant change interval for a Subaru Forester is typically every 30,000 miles or 2 years, whichever comes first. This helps ensure the cooling system continues to function properly and prevents potential damage to the engine.

Importance of Changing Coolant in a Subaru Forester

The coolant in a Subaru Forester serves several critical functions, including:

• Absorbing heat from the engine and transferring it to the radiator for cooling


• Preventing the engine from overheating


• Protecting the engine and cooling system components from corrosion and buildup

Over time, the coolant can become contaminated with dirt, rust, and other debris, reducing its effectiveness. Additionally, the coolant's chemical composition can break down, making it less able to perform its job properly. Changing the coolant at the recommended intervals helps ensure the cooling system continues to operate efficiently and protects the engine from damage.

Subaru Forester Coolant Change Procedure

Changing the coolant in a Subaru Forester typically involves the following steps:

1. Locate the radiator drain plug, usually at the bottom of the radiator, and drain the old coolant.


2. Refill the radiator with the recommended type and amount of new coolant, as specified in the owner's manual.


3. Start the engine and allow it to run until the thermostat opens and the coolant circulates through the system.


4. Top up the coolant level in the overflow tank as needed.


5. Dispose of the old coolant properly, as it can be harmful to the environment.

It's important to use the correct type of coolant recommended by Subaru, as using the wrong type can lead to compatibility issues and potential damage to the cooling system.

Factors That May Affect Coolant Change Interval

While the general recommendation is to change the coolant every 30,000 miles or 2 years, there are a few factors that may influence the actual change interval for a Subaru Forester:

• Driving Conditions: Vehicles used in harsher environments, such as towing heavy loads or operating in extreme temperatures, may require more frequent coolant changes.


• Coolant Type: Some coolants have a longer service life than others, so the recommended change interval may vary depending on the type of coolant used.


• Maintenance History: If the cooling system has been well-maintained and the coolant has been regularly checked, the change interval may be extended slightly.

It's always best to consult the Subaru Forester owner's manual or speak with a qualified mechanic to determine the optimal coolant change schedule for your specific vehicle and driving conditions.

How often should I do a coolant flush on my Subaru?

every 30,000 miles
On average, most Subaru vehicles require coolant flush service every 30,000 miles. However, the timing may vary based on the make and model of your vehicle.

Do Subaru's need special coolant?

Yes, Subarus need a specific coolant, primarily the factory-filled "Super Coolant," which is a special blue Subaru coolant. Before 2008, Subarus used a long-life green coolant. While a high-quality universal Asian blue coolant can be used, it's crucial to use the correct type for your specific Subaru model and year to ensure proper corrosion protection, especially for its aluminum engine components.
 
Coolant types and considerations

• Blue Subaru Super Coolant: This is the current standard, introduced after 2008, and is a premixed, long-life formula designed specifically for Subaru's aluminum engines. It has a much longer service interval than older coolants. 
• Green Subaru Long Life Coolant: This was used in Subarus before 2008. It is an ethylene glycol-based coolant that is not premixed and requires mixing with water to the correct ratio, which can be more challenging to get right. 
• Universal Asian Blue Coolant: A high-quality universal Asian blue coolant can be used as a substitute for Subaru's blue Super Coolant. This coolant is also designed to protect aluminum engines and can be a good option if you can't get the Subaru-brand product. 

Important tips

• Always check your owner's manual: The most accurate information for your specific Subaru model will be in your owner's manual. 
• Don't mix coolants: Never mix green and blue coolant, as they are not formulated to be compatible with each other. 
• Consider the warranty: If your car is still under warranty, using the specified Subaru coolant is recommended to avoid voiding the warranty. 
• Don't use universal coolants indiscriminately: While some universal coolants may work, it's crucial to ensure the universal coolant is specifically formulated for Asian vehicles to protect against corrosion and other damage. 

Is a coolant flush really necessary?

Yes, a coolant flush is necessary for routine preventive maintenance, as it removes debris and old, degraded coolant that can cause overheating, corrosion, and expensive engine damage over time. It cleans out rust and scale deposits, restores the coolant's ability to transfer heat efficiently, and prevents the buildup of acidic and contaminated fluid in the cooling system. 
You can watch this video to see why coolant flushes are important for your car's engine: 58sWhat Dennis DoesYouTube · Nov 15, 2018
Why a coolant flush is necessary

• Prevents engine overheating: Coolant can become contaminated with rust and scale, which can clog passages and block the system's ability to transfer heat. A flush removes these blockages and replaces old coolant with fresh fluid. 
• Protects against corrosion: Over time, coolant becomes acidic, which can corrode metal components in the engine and radiator. Flushing the system removes acidic fluid and replaces it with new coolant that contains anti-corrosive additives. 
• Maintains the effectiveness of coolant: Coolant contains additives that break down over time. A flush replaces old, ineffective coolant with new fluid, ensuring proper freeze protection and heat transfer. 
• Prevents costly repairs: By preventing overheating, corrosion, and clogs, a regular coolant flush helps avoid catastrophic and expensive engine damage. 
• Identifies underlying issues: A flush provides an opportunity for a mechanic to inspect the system. If oil or other contaminants are found in the old coolant, it can indicate other problems that need to be addressed. 

This video demonstrates how to perform a coolant flush: 30sChrisFixYouTube · Mar 6, 2015
When to get a coolant flush

• According to your manufacturer's schedule: Check your owner's manual for the recommended service intervals. 
• If you buy a used car: It is especially important to flush the coolant if you don't know the service history of a high-mileage used car. 
• If you notice signs of a problem: Look for signs of overheating, or if you find low coolant levels and suspect a leak or contamination. 

Can coolant last 100,000 miles?

Depending on the vehicle and the coolant, the average time between flushes is two years or 30,000 miles for silicated coolants and up to five years or 100,000 miles for an extended drain coolant. Periodically, the coolant needs to be tested every 50,000 miles.