The BMW 3 Series F30 335i, produced from 2012 to 2015, is a model that has been praised for its combination of performance, luxury, and advanced technology. This model, part of the sixth generation of the BMW 3 Series, features the N55 engine—a 3.0-liter turbocharged inline-six that provides an exhilarating driving experience. However, like any vehicle, the F30 335i is not without its issues. Over time, several common problems have been identified by owners and mechanics alike, which are important to consider if you own or are planning to purchase this vehicle. Understanding these issues and their potential impact on the vehicle can help you better maintain your BMW 335i and prevent costly repairs down the line.
BMW 3 Series F30 335i Engine Problems
The engine is the heart of any vehicle, and for the BMW 335i F30, the N55 engine is a critical component that contributes to the car’s performance and driving dynamics. However, the N55 engine is known to have a few issues that can affect the vehicle’s reliability and performance.
High-Pressure Fuel Pump (HPFP) Failure
One of the most significant and well-documented problems with the N55 engine is the failure of the high-pressure fuel pump (HPFP). The HPFP is essential for delivering the precise amount of fuel at the correct pressure to the engine’s fuel injectors. This high pressure is necessary for the engine to perform optimally, especially under demanding conditions. However, many BMW 335i owners have reported that the HPFP can fail prematurely.
When the HPFP begins to fail, you might notice symptoms such as long cranks during startup, particularly in cold weather, a loss of power during acceleration, and even engine stalling. In some cases, the engine may enter a “limp mode,” reducing power to protect the engine from further damage. This issue can be particularly dangerous if it occurs while driving, as it can lead to a sudden loss of power.
The cause of HPFP failure is often due to internal wear and tear, which can lead to a decrease in the pump’s ability to maintain the required fuel pressure. In some cases, the failure can be linked to fuel contamination or the use of poor-quality fuel, which can damage the pump over time.
Replacing the HPFP can be a costly repair, but it is necessary to restore the vehicle’s performance and reliability. BMW has issued recalls and extended warranties for HPFP-related issues in the past, so it is worth checking if your vehicle is covered under any such program.
Turbocharger Wastegate Rattle
Another common engine-related problem in the BMW 335i F30 is the turbocharger wastegate rattle. The N55 engine features a single twin-scroll turbocharger, which is responsible for boosting the engine’s power by forcing more air into the combustion chamber. The wastegate is a crucial component of the turbocharger system, as it regulates the amount of exhaust gas that bypasses the turbine, thereby controlling the boost pressure.
Over time, the wastegate mechanism can wear out, leading to a rattling noise, especially noticeable at idle or when decelerating. This rattle is caused by excessive play in the wastegate actuator, which can result in improper sealing of the wastegate. While the rattle itself may not immediately affect the vehicle’s performance, it can indicate that the turbocharger is beginning to fail.
If left unaddressed, a failing wastegate can lead to a loss of turbo boost, reduced engine performance, and increased emissions. In some cases, the wastegate failure can cause the turbocharger to fail altogether, which is a much more expensive repair. Some owners choose to replace the wastegate actuator or upgrade to an aftermarket turbocharger to resolve this issue.
Oil Leaks and Oil Consumption
The N55 engine is also known for being prone to oil leaks and excessive oil consumption. Oil leaks can occur from various points in the engine, including the valve cover gasket, oil filter housing gasket, and the oil pan gasket. Over time, these gaskets can deteriorate, leading to oil seeping out and potentially causing engine damage if not addressed.
Excessive oil consumption is another issue that some BMW 335i owners experience. The N55 engine’s turbocharger relies heavily on proper lubrication, and if the oil level drops too low, it can lead to turbocharger failure. Owners may notice that they need to top up the engine oil more frequently than expected, which can be a sign of excessive oil consumption.
It’s important to regularly check the oil level and inspect the engine for any signs of leaks. If you notice oil spots under the vehicle or a burning oil smell, it’s crucial to have the engine inspected by a professional to identify and repair any leaks. Replacing worn gaskets and seals can help prevent oil leaks and reduce oil consumption.
Cooling System Failures
The cooling system is vital for maintaining the engine’s temperature and preventing overheating, which can lead to severe engine damage. The BMW 335i F30’s cooling system, however, is known to have several weaknesses that can cause issues over time.
Water Pump and Thermostat Failures
One of the most common cooling system problems in the BMW 335i F30 is the failure of the electric water pump and thermostat. The water pump is responsible for circulating coolant through the engine and radiator, while the thermostat regulates the engine’s temperature by controlling the flow of coolant.
Many BMW 335i owners have reported that the water pump and thermostat can fail prematurely, often around 60,000 to 80,000 miles. When these components fail, the engine can overheat, leading to potential damage to the cylinder head, head gasket, and other engine components.
Symptoms of a failing water pump or thermostat include fluctuating engine temperatures, coolant leaks, and the illumination of the check engine light. In some cases, the vehicle may enter a limp mode to prevent further damage. Replacing the water pump and thermostat is essential to ensure the cooling system functions correctly and to avoid costly engine repairs.
Radiator and Cooling Hoses Issues
The radiator is another critical component of the cooling system, responsible for dissipating heat from the coolant. Over time, the radiator can become clogged with debris or suffer from corrosion, leading to reduced cooling efficiency and potential overheating.
Cooling hoses, which carry coolant between the engine and radiator, are also prone to wear and tear. As the vehicle ages, these hoses can develop cracks or leaks, leading to a loss of coolant and possible engine overheating. Regular inspection of the radiator and cooling hoses can help identify issues before they lead to more significant problems.
If you notice coolant leaks, rising engine temperatures, or the smell of coolant under the hood, it’s important to have the cooling system inspected and repaired as necessary. Replacing the radiator, hoses, and other components as needed can help maintain the cooling system’s effectiveness and prevent overheating.
Electrical Issues
Electrical problems are a frequent concern for BMW 335i F30 owners. These issues can range from minor inconveniences to more serious problems affecting the vehicle’s performance.
Battery and Charging System Failures
Many BMW 335i owners have reported issues with the battery and charging system. The battery may drain prematurely, or it may fail altogether, leaving the driver with a vehicle that won’t start. This issue can be particularly frustrating because it often occurs without warning.
The charging system, which includes the alternator and voltage regulator, is responsible for keeping the battery charged and ensuring that all electrical systems have the power they need to operate. If the charging system fails, it can lead to a dead battery and, in some cases, electrical malfunctions throughout the vehicle.
To prevent battery and charging system issues, it’s important to regularly test the battery and alternator and replace them as necessary. Additionally, ensuring that all electrical connections are clean and secure can help maintain the charging system’s reliability.
Sensor Malfunctions
The BMW 335i F30 is equipped with numerous sensors that monitor various aspects of the vehicle’s operation, including engine performance, emissions, and safety systems. However, these sensors can sometimes malfunction, leading to false warning lights on the dashboard.
One common issue is the persistent illumination of the check engine light, even when there is no underlying problem. This can be caused by a faulty sensor, such as an oxygen sensor or mass airflow sensor, which may send incorrect data to the vehicle’s computer.
Another issue is with the airbag warning light, which may stay on even if the airbag system is functioning correctly. This can be due to a faulty sensor or a problem with the airbag control module.
Diagnosing sensor malfunctions can be challenging, as it often requires specialized diagnostic equipment. If you experience persistent warning lights or other symptoms, it’s essential to have the vehicle inspected by a professional who can accurately diagnose and resolve the issue.
iDrive System Issues
The iDrive system in the BMW 335i F30 is responsible for controlling many of the vehicle’s electronic functions, including navigation, entertainment, and climate control. While the iDrive system is generally reliable, some owners have reported problems with it freezing, malfunctioning, or even failing altogether.
These issues can range from minor annoyances, such as the system taking longer to boot up, to more significant problems, like the entire system becoming unresponsive. In some cases, a software update from BMW can resolve these issues, but in other cases, the iDrive unit may need to be replaced.
It’s important to keep the iDrive system software up to date and to address any issues as soon as they arise. Regular maintenance of the system, including ensuring that the vehicle’s battery is in good condition, can help prevent iDrive problems.
Transmission Problems
The transmission is a critical component of the BMW 335i F30, and several issues can arise that affect its performance.
Rough Shifting
One of the most common transmission problems reported by BMW 335i F30 owners is rough shifting. This issue can manifest as a delay in shifting, harsh or jerky gear changes, or even the transmission slipping out of gear. These symptoms can be particularly noticeable when accelerating or decelerating, and they can make the vehicle difficult to drive smoothly.
Rough shifting is often caused by issues with the transmission fluid, such as low fluid levels or old, degraded fluid. Regular transmission fluid changes can help prevent this problem, but if the issue persists, it may indicate a more serious problem with the transmission itself.
Mechatronic Unit Failure
Another transmission-related issue in the BMW 335i F30 is the failure of the mechatronic unit. The mechatronic unit is responsible for controlling the transmission’s hydraulic functions, and when it fails, it can lead to a variety of problems, including erratic shifting, transmission warning lights, and even complete transmission failure.
Replacing the mechatronic unit can be expensive, but it is necessary to restore proper transmission function. Regular transmission fluid changes and inspections can help detect early signs of mechatronic unit failure and prevent more severe issues.
Transmission Cooler Problems
The transmission cooler in the BMW 335i F30 is responsible for keeping the transmission fluid at the correct temperature. If the cooler fails, the transmission can overheat, leading to damage.
Symptoms of a failing transmission cooler include transmission fluid leaks, overheating, and transmission warning lights. If you notice these symptoms, it’s important to have the transmission cooler inspected and replaced if necessary to prevent further damage to the transmission.
Suspension and Steering Issues
The BMW 335i F30 is known for its sharp handling and responsive steering, but some owners encounter problems with the suspension and steering components.
Suspension Bushing Wear
The suspension bushings in the BMW 335i F30 are prone to wear over time. These rubber components cushion the suspension and help absorb shocks from the road, but they can deteriorate and crack as the vehicle ages.
Worn suspension bushings can lead to a variety of problems, including clunking noises, uneven tire wear, and a harsh ride. If the bushings are not replaced, they can affect the vehicle’s handling and overall ride comfort.
Control Arm Failure
Control arms are another critical component of the suspension system in the BMW 335i F30. They connect the wheels to the chassis and allow the suspension to move up and down.
Some 335i owners have reported issues with the control arms, such as excessive wear or even failure. Symptoms of a failing control arm include clunking noises, poor handling, and uneven tire wear. Replacing the control arms is necessary to maintain proper suspension function and ensure safe handling.
Electric Power Steering Issues
The steering system is another area where problems can arise in the BMW 335i F30. Some owners have reported issues with the electric power steering system, such as a loss of power assist or a failure of the steering motor.
These problems can make the vehicle difficult to steer, especially at low speeds. In some cases, a software update can resolve these issues, but in others, the steering motor or other components may need to be replaced.
Brake System Problems
The brake system is one of the most critical safety components of any vehicle, and the BMW 335i F30 is no exception. However, some owners have reported problems with the brake system that can affect its performance and safety.
Brake Pad and Rotor Wear
The BMW 335i F30 is equipped with high-performance brakes that are designed to provide excellent stopping power. However, the brake pads and rotors are known to wear out relatively quickly, especially under aggressive driving conditions.
Worn brake pads can lead to reduced braking performance, increased stopping distances, and even damage to the rotors. If the rotors become damaged, they may need to be replaced, which can be an expensive repair.
It’s important to regularly inspect the brake pads and rotors and replace them when they become worn. High-quality aftermarket pads and rotors can help improve the durability and performance of the brake system.
Brake Caliper Problems
The brake calipers in the BMW 335i F30 are responsible for squeezing the brake pads against the rotors to slow the vehicle down. Some owners have reported issues with the calipers, such as sticking or seizing.
A sticking or seized caliper can cause the brakes to drag, leading to uneven braking, reduced fuel efficiency, and premature wear of the brake pads and rotors. If you notice any of these symptoms, it’s important to have the brake calipers inspected and replaced if necessary.
Brake Fluid Maintenance
Brake fluid is a crucial component of the brake system, as it transfers the force from the brake pedal to the calipers. However, brake fluid is hygroscopic, meaning it absorbs moisture over time.
If moisture enters the brake fluid, it can lead to corrosion of the brake system components and a reduction in braking performance. Regular brake fluid changes are essential to maintaining the health of the brake system and ensuring safe braking.
Fuel System Problems
The fuel system of the BMW 335i F30 can also present issues that affect the vehicle’s performance.
Fuel Injector Failures
One common fuel system problem in the BMW 335i F30 is the failure of the fuel injectors. The fuel injectors are responsible for delivering the correct amount of fuel to the engine, and when they fail, it can lead to a variety of problems.
Symptoms of failing fuel injectors include rough idling, poor fuel economy, and engine misfires. In some cases, the engine may run too rich or too lean, which can cause damage to the catalytic converter and other components.
If you notice any of these symptoms, it’s important to have the fuel injectors inspected and replaced if necessary. High-quality aftermarket injectors can help improve the performance and reliability of the fuel system.
High-Pressure Fuel Pump (HPFP) Issues
As mentioned earlier, the high-pressure fuel pump (HPFP) is a critical component of the fuel system in the BMW 335i F30. If the HPFP fails, it can lead to a variety of issues, including long cranks during startup, loss of power, and engine stalling.
Regular maintenance of the fuel system, including using high-quality fuel and fuel additives, can help prevent HPFP issues. If you experience any symptoms of a failing HPFP, it’s important to have the pump inspected and replaced if necessary.
Conclusion
The BMW 3 Series F30 335i is an outstanding vehicle, but like all cars, it has its share of common problems. Being aware of these issues can help you take the necessary precautions to maintain your vehicle's performance and longevity.
For those experiencing any of these problems, it’s crucial to address them promptly to avoid further damage. At European Auto Pro, located at 253 Goodwood Road, Kings Park, 5034, South Australia, our team of experienced technicians specializes in diagnosing and repairing BMW vehicles. Whether you're dealing with engine problems, cooling system failures, or any other issue, we’re here to help keep your BMW 335i running smoothly.