Experiencing a sloshing sound in your 2017 Subaru Impreza can be unsettling, and it often points to an issue within your vehicle’s cooling system. This sound is frequently a sign of air trapped in the system, and understanding why this happens and how to address it is crucial for maintaining your Impreza’s engine health. This article will explain the common cause of this sloshing noise and guide you on the necessary steps to take.
Decoding Your 2017 Impreza’s Cooling System and Overflow Tank
Your 2017 Impreza, like many modern vehicles, utilizes a coolant overflow tank as an integral part of its engine cooling system. This system is designed to manage the fluctuations in coolant volume that occur due to temperature changes during engine operation.
When your Impreza’s engine runs, the coolant heats up and expands. This expanded coolant needs somewhere to go, and that’s where the overflow tank comes in. As the coolant expands, excess fluid is pushed into the overflow tank through a valve located in the radiator cap. Interestingly, your Impreza actually has two coolant caps, but it’s the lower pressure-rated cap, typically found on the radiator itself, that primarily facilitates this fluid transfer.
Alt text: Close-up of a radiator cap on a 2017 Subaru Impreza, highlighting its role in the cooling system’s pressure regulation.
Conversely, when you turn off your 2017 Impreza’s engine and it begins to cool down, the coolant contracts in volume. This contraction creates a vacuum within the cooling system. The valve in the radiator cap then opens, allowing the coolant stored in the overflow tank to be drawn back into the engine’s cooling system, ensuring the system remains full.
This expansion and contraction cycle repeats every time your engine heats up and cools down. Subaru employs a system that, while efficient, is open to the atmosphere at the overflow tank’s suction tube. This open design means a small amount of coolant evaporation is always occurring. Consequently, your 2017 Impreza’s cooling system is constantly losing a tiny bit of coolant over time.
The Link Between Low Coolant and Sloshing Sounds in Your 2017 Impreza
The described coolant management system is highly dependent on maintaining the correct coolant level in the overflow tank. The tank has markings indicating “Full” and “Low” levels. Ideally, the coolant level should always be at the “Full” line when the engine is cold. While a slight drop to the “Low” line is generally acceptable, consistently letting the overflow tank run dry can lead to problems.
If the coolant level in the overflow tank drops too low and runs out, the cooling system can start drawing in air instead of coolant as it cools down. This is the primary reason you might hear a sloshing sound in your 2017 Impreza. The sound is literally the coolant and air mixture moving around within the system.
Alt text: The coolant overflow tank in a 2017 Subaru Impreza engine bay, emphasizing the importance of maintaining the coolant level between the ‘Full’ and ‘Low’ lines.
Air in the cooling system is detrimental because air is a poor heat conductor compared to coolant. Its presence reduces the cooling system’s efficiency, potentially leading to engine overheating and damage to critical engine components. Therefore, addressing a sloshing sound and the likely air in the system is not just about eliminating the noise, but about safeguarding your 2017 Impreza’s engine.
Correcting Air in Your 2017 Impreza’s Cooling System: Seek Professional Help
Now that you understand the cause of the sloshing sound, you face the task of removing the air from your 2017 Impreza’s cooling system and refilling it correctly. This process, known as “bleeding” the cooling system, can be somewhat complex and requires careful attention to detail. Specialized tools, like coolant fill devices, can assist in this process.
Furthermore, it’s absolutely critical to use the correct type of coolant in your 2017 Impreza. Subaru specifically mandates the use of “Subaru Super Coolant.” Using any other type of coolant can lead to corrosion and damage within your cooling system, potentially voiding warranties and causing further issues.
Given the intricacies of bleeding a cooling system and the necessity of using the correct coolant, it is strongly recommended to seek assistance from a qualified automotive technician. Unless you possess advanced mechanical skills and a thorough understanding of automotive cooling systems, attempting this repair yourself could lead to further complications or engine damage.
Ignoring a sloshing sound in your 2017 Impreza is not advisable. It’s a clear indicator of a problem that needs prompt attention. Addressing it quickly by seeking professional service will ensure your vehicle’s cooling system functions correctly, protecting your engine and preventing potentially expensive repairs down the road.
