2019 BMW 440i Gran Coupe Has A Coolant Leak

Diagnosing Coolant Leak Issues in Your 2019 BMW 440i Gran Coupe and Effective Repair Strategies

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
50% chance it's the
Loose Hose Connections
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25% chance it's the
Radiator
0%
25% chance it's the
Water Pump
The most common reasons a 2019 BMW 440i Gran Coupe has a coolant leak are loose hose connections, a broken radiator, or a failed water pump.
  • Loose Hose Connections: A loose hose connection can lead to vacuum leaks or fluid loss, resulting in poor engine performance or overheating.
  • Radiator: A damaged or clogged radiator can impede coolant flow, resulting in engine overheating and reduced cooling efficiency.
  • Water Pump: A failing water pump can lead to coolant leaks or overheating due to inadequate circulation of coolant in the engine.
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.

How much does it cost to fix a 2019 BMW 440i Gran Coupe has a coolant leak?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

When the head gasket begins to fail, the engine may have no symptoms at all. They only begin to occur when the leak has reached an engine oil passage, engine coolant passage or the engine cylinder.

When that happens, the engine may be very difficult to start, and run roughly when idling. There may be oil or coolant leaking, and the engine may begin to overheat, or at least run hot. At this point, there may be coolant in the engine oil pan — this will look creamy and lighter in color than the oil. Also, the radiator or engine coolant reservoir may have a gurgling sound, the presence engine oil, or smell of combustion. And the check engine light will come on.

The coolant being burned in the engine will produce white exhaust that smells sweet, like engine coolant. When the head gasket fails completely, the engine will overheat within minutes of starting, will stall and then won't restart.

A failing heater core may cause the car's interior to smell like engine coolant. The smell will become worse when the heater is turned on. The engine may also begin to run hotter until the vehicle is repaired.

The worst-case scenario is the engine overheating, which can cause extensive engine damage.

If the heater core is clogged, the air that blows when the heater is turned on will not be very hot.

Problems with the intake manifold gasket can create the following symptoms:

  • Illuminated check engine light
  • Erratic engine performance
  • Oil and coolant leaks
  • Poor gas mileage
  • Stalling

» LEARN MORE: Intake manifold gasket symptoms

A failing radiator can cause the engine to run hot or overheat. Most radiators are made of metal and plastic. The plastic parts can become brittle and crack over time, causing a leak of coolant (typically green or pink in color). All manufacturers have a recommended service interval for coolant renewal. As the coolant ages, the additives breakdown and being to form solid deposits. These deposits will build up in the passages of the cooling system and will eventually clog components, including the radiator. A leaking or clogged radiator must be replaced. Some automatic transmission cars will also have a transmission cooler integrated into the radiator. Lines going to and from the transmission circulate transmission fluid to help cool the transmission in heavy duty applications such as towing or off-roading. If this integrated cooler fails, it can allow transmission fluid and coolant to mix. This will causing shifting issues in addition to overheating.

A coolant leak may be noted from the hoses. Coolant hoses can be damaged by oil leaks, or age. This will lead to swelling or cracking, it is suggested to replace the hoses before they begin leaking to avoid potential overheating.

The bad thermostat can cause two different sets of problems, depending on whether it's stuck open or stuck closed.

A thermostat that is stuck open can cause the engine to run colder than normal and turn on the check engine light. It may also cause poor fuel mileage and the heater to blow cool air.

A thermostat that is stuck closed will cause the vehicle to overheat. If a new thermostat doesn't resolve engine temperature problems, the cooling system needs to be checked for other issues.

» LEARN MORE: Signs of a bad thermostat, and how to fix it

The two most common signs of a bad pump are leaks and noises.

Leaking water pumps can result in damage to the drive and timing belts, and cause the engine to overheat. A failed water pump can be caused by other problems in the cooling system, such as a bad thermostat, radiator or head gasket.

What steps should I take to diagnose a coolant leak in my 2019 BMW 440i Gran Coupe?

When diagnosing a coolant leak in your 2019 BMW 440i Gran Coupe, it's essential to adopt a systematic approach that begins with simple visual inspections and progresses to more complex diagnostics. Start by conducting a thorough visual inspection under the vehicle, focusing on areas such as the radiator, hoses, and water pump for any visible signs of coolant. Next, monitor the coolant level in the reservoir; a sudden drop can be a clear indicator of a leak. If these initial checks do not reveal the source, consider performing a pressure test on the cooling system, which can help pinpoint leaks by observing pressure drops. Additionally, inspect the radiator for corrosion or damage, and examine all hoses and connections for cracks or loose fittings. Pay special attention to the water pump, as leaks often originate from this component. For leaks that are not easily visible, adding UV dye to the coolant can be an effective method; using a UV light will help you identify any hidden leaks. If you still cannot locate the source of the leak after these steps, it may be time to consult a professional mechanic or a BMW dealership for further assistance. This structured approach not only helps in identifying the issue efficiently but also ensures that you address the problem before it escalates.

What are the common causes of a coolant leak in a 2019 BMW 440i Gran Coupe?

When dealing with coolant leaks in a 2019 BMW 440i Gran Coupe, it's crucial to understand the common culprits that may be at play. A faulty water pump is often a primary suspect, as it can fail to circulate coolant properly, leading to leaks. Additionally, a damaged or corroded radiator can compromise the cooling system, resulting in fluid loss. Over time, the hoses that transport coolant can wear out, leading to cracks or holes that allow coolant to escape. It's also important to check the hose clamps; if they are loose or damaged, they may not secure the hoses adequately, causing leaks. In more severe cases, a cracked engine block or a leaking heater core can lead to significant coolant loss, potentially affecting the vehicle's performance. Regular inspections and maintenance are key to identifying these issues early, ensuring that your BMW remains in optimal condition and preventing costly repairs down the line.

How urgent is it to address a coolant leak in a 2019 BMW 440i Gran Coupe?

When it comes to a coolant leak in your 2019 BMW 440i Gran Coupe, urgency cannot be overstated. Coolant is essential for maintaining optimal engine temperature, and any leak can lead to overheating, which poses a serious risk of engine damage. If the engine runs hot due to insufficient coolant, it may not only result in a breakdown but could also lead to catastrophic engine failure, incurring costly repairs. Additionally, neglecting a coolant leak can adversely affect your vehicle's performance, leading to decreased fuel efficiency and further mechanical issues. For DIY enthusiasts, it is crucial to recognize that early intervention can save you from more extensive repairs down the line. Therefore, if you notice any signs of a coolant leak, such as puddles under your vehicle or a drop in coolant levels, it is imperative to inspect the cooling system immediately and address any issues to ensure the safety and longevity of your BMW.

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