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:
» 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.
To effectively diagnose a coolant leak in your 2011 BMW 335i xDrive, begin with a careful inspection of the coolant reservoir, looking for low levels or discoloration that could signal a leak. Next, examine the coolant hoses and clamps for any visible damage, such as cracks or loose connections, as these are often the source of leaks. It's also important to inspect the radiator for leaks around the seams and end tanks. Be mindful of common indicators of a coolant leak, including a sweet smell from the engine or puddles of coolant under your vehicle. Additionally, check for any dashboard warning lights that may alert you to low coolant levels. If you observe steam or smoke coming from the engine, address this issue immediately, as it may point to a more serious problem. Finally, if you suspect a blown head gasket, monitor for signs of overheating and inspect the engine oil for any signs of coolant mixing. By following this structured diagnostic approach, you can effectively identify and resolve coolant leak issues, helping to maintain the performance and reliability of your BMW.
When tackling a coolant leak in a 2011 BMW 335i xDrive, it's essential to understand the common problems that may arise within the cooling system. One of the primary culprits is the water pump, which can fail due to wear and tear over time, leading to coolant loss. Additionally, the radiator and expansion tank are critical components that can develop leaks, often exacerbated by age or physical damage. Hoses, particularly the vent hose connecting the upper radiator hose to the coolant reservoir, are also prone to breaking, especially if mishandled during maintenance. It's important to check the coolant reservoir cap as well, as a faulty cap can allow coolant to escape without any visible leaks. While the color of the coolant may vary, it is crucial to use the correct type for your vehicle to avoid further complications. Lastly, neglecting regular maintenance can lead to more severe issues, such as a blown head gasket, which not only causes coolant leaks but can also result in significant engine damage. By identifying these common problems early, DIYers can take proactive steps to repair their cooling system and prevent costly repairs down the line.
Addressing a coolant leak in your 2011 BMW 335i xDrive is not just a matter of convenience; it is a pressing concern that can significantly impact the longevity and performance of your vehicle. Ignoring a coolant leak can lead to severe engine overheating, which may result in catastrophic damage such as blown head gaskets or complete engine failure. The components most commonly responsible for these leaks, including the water pump, radiator, and hoses, can deteriorate over time, making early detection crucial. By identifying and repairing the leak promptly, you not only safeguard your engine from costly repairs but also enhance your vehicle's overall reliability. Therefore, if you notice any signs of coolant leakage, it is imperative to act swiftly to prevent further complications and ensure your BMW remains in optimal condition.
See what others are asking about their BMW 335i xDrive. Get answers from RepairPal's community of auto experts and enthusiasts.
Read about related problems experienced by other BMW 335i xDrive drivers like you.