BMW 135is Is Overheating

Common Causes of Overheating in Your BMW 135is and How to Prevent Engine Damage

Find Repair Location
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 BMW 135is 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.

Troubleshooting Overheating Issues in a BMW 135is

When faced with overheating issues in your BMW 135is, begin your diagnostic approach by checking the coolant levels, as low coolant can often be the simplest and most common cause of overheating. If the coolant is adequate, inspect for any visible leaks in the cooling system, including hoses and connections, which can lead to coolant loss and subsequent overheating. Next, examine the radiator for blockages or damage, as a compromised radiator can hinder proper cooling. If these initial checks do not reveal the problem, assess the thermostat's functionality; a stuck thermostat can prevent coolant circulation, leading to overheating. Additionally, inspect the water pump for any signs of failure, such as unusual noises or leaks, as a malfunctioning water pump can severely impact the cooling system's efficiency. If all these components appear to be in good condition, consider more complex issues such as engine blockages or head gasket failures, which may require professional assistance. By following this structured approach, you can effectively diagnose and address overheating issues in your BMW 135is, ensuring your vehicle remains in optimal condition.

What Are the Common Causes of Overheating in a BMW 135is?

Understanding the common causes of overheating in a BMW 135is is vital for any DIY owner looking to maintain their vehicle's performance. One of the primary culprits is coolant leaks, which can occur due to damaged hoses or a cracked radiator, significantly reducing the cooling system's efficiency. Additionally, issues with the thermostat and water pump can disrupt the flow of coolant, leading to improper temperature regulation and potential engine overheating. Clogged cooling systems are another concern, as blockages can prevent the necessary circulation of coolant, exacerbating overheating problems. It's also important to use the correct type of coolant; using an inappropriate coolant can further contribute to overheating issues. Regular maintenance practices, such as checking for leaks, monitoring coolant levels, and ensuring that the thermostat and water pump are functioning correctly, can help prevent these overheating issues and extend the life of your BMW 135is. If you notice signs of overheating, it’s wise to conduct a thorough inspection or consult a qualified technician to address any underlying problems before they escalate.

What to Do When Your BMW 135is is Overheating?

When your BMW 135is begins to overheat, it’s essential to act swiftly to prevent severe engine damage and ensure your safety on the road. Ignoring symptoms such as warning lights, unusual smells, or smoke can lead to catastrophic failures, making it crucial to stop driving immediately. Once the vehicle is safely parked, assess the situation by checking the coolant levels and inspecting for visible leaks. If you notice any issues, it’s advisable to consult a professional mechanic who specializes in BMWs, as they can accurately diagnose the underlying problem. Regular maintenance, including coolant flushes and system checks, can significantly reduce the risk of overheating. By being proactive and attentive to your vehicle’s needs, you can maintain its performance and longevity, ensuring that your BMW 135is remains in optimal condition.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

BMW 135is Overheating Causes & Repair Costs | RepairPal