2021 Mazda 6 Is Overheating

Common Causes of Overheating in Your 2021 Mazda 6 and How to Resolve Them Effectively

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Reviewed by
Bo Fader
Written by RepairPal Car Genius
Updated January 14, 2025
0%
24% chance it's the
Thermostat
0%
41% chance it's the
Coolant leak (water pump, radiator, hose etc.)
0%
32% chance it's the
Radiator Fan
0%
3% chance it's
Something else
The most common reasons a 2021 Mazda 6 is overheating are a coolant leak (water pump, radiator, hose etc.), the radiator fan, or a failed thermostat.
  • Thermostat: A faulty thermostat can cause the engine to overheat or run too cool by failing to regulate the flow of coolant properly.
  • Coolant leak (water pump, radiator, hose etc.): A coolant leak can occur due to a damaged hose, a failing water pump, or a compromised radiator, leading to loss of coolant and potential engine overheating.
  • Radiator Fan: A faulty radiator fan can lead to engine overheating due to insufficient airflow over the radiator.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

What steps should I take to diagnose the overheating issue in my 2021 Mazda 6?

When diagnosing an overheating issue in your 2021 Mazda 6, it's crucial to follow a methodical approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by verifying the coolant level in both the radiator and the reservoir, as insufficient coolant can lead to overheating. If the coolant is at the correct level, inspect the cooling system for any visible leaks, paying close attention to hoses, the radiator, and the water pump. Next, check the functionality of the radiator fan; a malfunctioning fan can significantly impede the cooling process. After confirming the fan's operation, test the thermostat to ensure it opens and closes properly, as a faulty thermostat can disrupt the engine's temperature regulation. Additionally, assess the water pump for efficiency, since a failing pump can hinder coolant circulation. It's also important to inspect the radiator for any blockages or damage that could restrict coolant flow. If needed, conduct a pressure test on the cooling system to detect any leaks or weak spots. Lastly, ensure that all components of the cooling system, including hoses, belts, and the radiator cap, are in good working order. By systematically following these steps, you can effectively diagnose and address the overheating issue in your Mazda 6.

What are the common causes of overheating in a 2021 Mazda 6?

Understanding the common causes of overheating in a 2021 Mazda 6 is essential for any DIY enthusiast looking to maintain their vehicle. One of the primary culprits is low coolant levels, which can occur due to evaporation or leaks, preventing the engine from receiving adequate cooling. Additionally, cooling system leaks can arise from damaged hoses, a failing water pump, or a compromised radiator, all of which can lead to a significant loss of coolant. Another frequent issue is a faulty thermostat, which may fail to open or close properly, disrupting the flow of coolant and causing the engine to overheat. Clogged radiators can also be problematic, as debris buildup can hinder the radiator's ability to dissipate heat effectively. Lastly, issues with the cooling fan, whether due to a malfunctioning motor or relay, can impede airflow through the radiator, exacerbating overheating problems. Regular maintenance and timely inspections of these components can help prevent overheating and ensure the longevity of your Mazda 6.

How urgent is it to address the overheating issue in my 2021 Mazda 6?

Addressing the overheating issue in your 2021 Mazda 6 is of utmost urgency, as neglecting this problem can lead to severe consequences for both your vehicle and your safety. Overheating can cause catastrophic engine damage, including the failure of essential components like the head gasket, radiator, or water pump, which can result in costly repairs or even total engine failure. Moreover, the risks extend beyond mechanical failures; an overheating engine can lead to dangerous situations on the road, such as sudden breakdowns or fire hazards. Regular maintenance and immediate attention to any signs of overheating not only preserve the performance of your Mazda 6 but also ensure your safety and the longevity of your vehicle. Therefore, if you notice any symptoms of overheating, it is crucial to act swiftly to prevent more significant issues down the line.

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