The BMW 3 Series F34 335i xDrive, known as the Gran Turismo (GT), combines the versatility of a hatchback with the performance and luxury that BMW enthusiasts have come to expect. Equipped with the N55 engine—a 3.0-liter turbocharged inline-six—and BMW’s xDrive all-wheel-drive system, the 335i xDrive GT offers an engaging driving experience with added practicality. However, like any vehicle, the 335i xDrive has its share of common problems that owners should be aware of. Understanding these issues can help you maintain your vehicle's performance and longevity, avoiding costly repairs and ensuring a smooth and enjoyable driving experience.
BMW 3 Series F34 335i xDrive Engine Problems
The BMW 335i xDrive F34 is powered by the N55 engine, which is widely regarded for its balance of power and efficiency. Despite its strengths, the N55 engine is known to have several 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 xDrive 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 xDrive 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.
Valve Cover Gasket Leaks
The valve cover gasket in the N55 engine is another component prone to leaks. The valve cover gasket seals the top of the engine and prevents oil from leaking out. Over time, the gasket can become brittle and crack, leading to oil leaks.
Oil leaks from the valve cover gasket can cause oil to drip onto the exhaust manifold, which can create a burning smell and, in some cases, smoke. This issue not only affects the cleanliness of the engine bay but can also lead to more significant engine problems if the oil levels drop too low. Regular inspection and timely replacement of the valve cover gasket can help prevent these leaks and maintain the engine's performance.
Oil Filter Housing Gasket Leaks
Another common issue reported by BMW 335i xDrive owners is leaks from the oil filter housing gasket. The oil filter housing gasket is responsible for sealing the connection between the oil filter housing and the engine block. Over time, this gasket can become brittle and deteriorate, leading to oil leaks. These leaks can cause a drop in oil pressure, which is critical for the lubrication and cooling of the engine components.
Signs of an oil filter housing gasket leak include oil spots under the vehicle, a burning oil smell, and a decrease in oil levels. If left unaddressed, this issue can lead to insufficient lubrication of the engine's moving parts, resulting in increased wear and potentially severe engine damage. Replacing the gasket as part of regular maintenance can help prevent these leaks and ensure the longevity of the engine.
Electric Water Pump Failure
The N55 engine in the BMW 335i xDrive is equipped with an electric water pump, which is responsible for circulating coolant through the engine to maintain optimal operating temperatures. Unlike traditional belt-driven water pumps, the electric water pump is more efficient but also more prone to failure.
One of the common issues with the electric water pump is premature failure, often occurring around 60,000 to 80,000 miles. Symptoms of a failing water pump include fluctuating engine temperatures, coolant leaks, and the illumination of the check engine light. If the water pump fails completely, the engine can overheat, leading to severe damage, such as a blown head gasket or warped cylinder head.
Replacing the electric water pump is an expensive but necessary repair to prevent catastrophic engine damage. Regular inspection of the cooling system and timely replacement of the water pump can help maintain the reliability of the N55 engine.
Turbocharger Issues
The turbocharger in the BMW 335i xDrive is a key component that enhances the engine’s performance, but it can also be a source of problems, especially as the vehicle ages or if regular maintenance is neglected.
Turbocharger Wastegate Rattle (Revisited)
As mentioned earlier, the wastegate rattle is a common issue in the N55 engine’s turbocharger system. This problem is often caused by wear and tear in the wastegate actuator, leading to a loose connection that results in the characteristic rattle noise. While the rattle itself may not immediately affect performance, it can indicate underlying issues that, if left unchecked, could lead to turbocharger failure.
Turbocharger Oil Leaks
Turbochargers rely on a steady supply of oil for lubrication and cooling. However, over time, the seals within the turbocharger can wear out, leading to oil leaks. If left unaddressed, oil leaks can cause the turbocharger to fail, resulting in significant engine damage.
Symptoms of a turbocharger oil leak include blue smoke from the exhaust, oil spots under the vehicle, and a drop in oil levels. If you notice any of these symptoms, it's important to have the turbocharger inspected and repaired or replaced as necessary. Regular oil changes and the use of high-quality synthetic oil can help prolong the life of the turbocharger seals and prevent leaks.
Charge Pipe Failure
The charge pipe in the BMW 335i xDrive’s N55 engine is responsible for carrying pressurized air from the turbocharger to the engine’s intake manifold. In many cases, the charge pipe is made of plastic, which can become brittle over time and crack under the high pressure generated by the turbocharger.
If the charge pipe fails, it can cause a loss of boost pressure, leading to reduced engine performance and triggering the check engine light. A failed charge pipe can also lead to an increase in turbo lag, where there is a noticeable delay between pressing the accelerator and the engine responding. This issue can significantly affect the driving experience, particularly in a vehicle known for its performance like the 335i xDrive.
To prevent charge pipe failure, many owners choose to upgrade to an aftermarket metal charge pipe, which offers greater durability and resistance to cracking under pressure. This upgrade can improve the reliability of the turbocharging system and maintain the vehicle's performance.
Transmission Problems
The BMW 335i xDrive F34 is equipped with the 8-speed ZF automatic transmission, which is widely regarded for its smooth and responsive shifting. However, like any mechanical component, the transmission can develop issues over time, particularly if the vehicle is driven aggressively or if regular maintenance is neglected.
Rough Shifting
Rough shifting is a common issue reported by some BMW 335i xDrive owners. This issue can manifest as harsh or jerky gear changes, delayed shifting, or even the transmission slipping out of gear. These symptoms can make the vehicle difficult to drive smoothly and can significantly detract from the overall driving experience.
Rough shifting is often caused by issues with the transmission fluid, such as low fluid levels or old, degraded fluid. The ZF 8-speed transmission is particularly sensitive to the condition of the transmission fluid, and neglecting to change the fluid at regular intervals can lead to shifting problems. Regular transmission fluid changes, as recommended by BMW, are essential to maintaining smooth shifting and prolonging the life of the transmission.
If rough shifting persists despite regular fluid changes, it may indicate a more serious problem with the transmission, such as a failing valve body or worn clutches. In such cases, professional diagnosis and repair are required to prevent further damage and ensure the transmission continues to operate properly.
Mechatronic Unit Problems
The mechatronic unit in the ZF 8-speed automatic transmission is responsible for controlling the hydraulic functions of the transmission. This complex component integrates electronic control with hydraulic actuation to manage gear changes seamlessly. However, the mechatronic unit can develop issues over time, particularly in high-mileage vehicles or those that have been driven aggressively.
Symptoms of mechatronic unit failure include erratic shifting, transmission warning lights on the dashboard, and in severe cases, complete transmission failure. If the mechatronic unit fails, it can lead to a loss of control over gear changes, making the vehicle difficult to drive and potentially leaving it stuck in a single gear.
Replacing the mechatronic unit can be expensive, but it is necessary to restore proper transmission function. Regular transmission maintenance, including fluid changes and inspections, can help detect early signs of mechatronic unit failure and prevent more severe issues.
Transmission Oil Cooler Problems
The transmission oil cooler in the BMW 335i xDrive is responsible for maintaining the temperature of the transmission fluid, ensuring it remains within the optimal range for smooth and reliable operation. If the transmission oil cooler fails, it can lead to overheating of the transmission fluid, which can cause the transmission to slip, shift harshly, or even fail completely.
Symptoms of a failing transmission oil cooler include transmission fluid leaks, a burning smell from the transmission area, and the transmission warning light illuminating on the dashboard. If you experience any of these symptoms, it’s important to have the transmission oil cooler inspected and replaced if necessary to prevent further damage to the transmission.
xDrive System Issues
The xDrive all-wheel-drive system in the BMW 335i F34 is designed to enhance traction and stability, particularly in adverse weather conditions. While the xDrive system is generally reliable, it can develop issues over time, particularly if the vehicle is driven in harsh conditions or if regular maintenance is neglected.
Transfer Case Problems
The transfer case is a critical component of the xDrive system, responsible for distributing power between the front and rear wheels. Over time, the transfer case can develop issues, particularly if the fluid inside is not changed at regular intervals. Common problems with the transfer case include worn gears, faulty actuators, and fluid leaks.
Symptoms of transfer case problems include grinding noises, vibrations, difficulty engaging the all-wheel-drive system, and a noticeable drop in fuel efficiency. If the transfer case fails completely, it can cause the vehicle to lose its all-wheel-drive capability, which can significantly affect handling and traction, especially in slippery or off-road conditions.
Regular maintenance of the xDrive system, including changing the transfer case fluid at the intervals recommended by BMW, can help prevent these issues. If you notice any symptoms of transfer case problems, it’s important to have the transfer case inspected and repaired or replaced if necessary to ensure the continued reliability of the xDrive system.
Driveshaft Issues
The driveshaft in the BMW 335i xDrive is responsible for transferring power from the transfer case to the front and rear differentials, which then distribute power to the wheels. Over time, the driveshaft can develop issues, particularly if the vehicle is driven on rough roads or in off-road conditions.
Symptoms of driveshaft problems include vibrations at high speeds, clunking noises when shifting or accelerating, and difficulty accelerating smoothly. If the driveshaft fails, it can lead to a loss of power to the wheels, making the vehicle difficult or impossible to drive.
Driveshaft issues can lead to more serious problems if not addressed, including damage to the transmission or differential. Regular inspection of the driveshaft, particularly if the vehicle is driven in harsh conditions, can help detect issues early and prevent more severe problems. If you notice any symptoms of driveshaft problems, it’s important to have the driveshaft inspected and repaired or replaced as necessary.
Electrical Issues
Electrical problems are a common concern for many modern vehicles, including the BMW 335i xDrive. These issues can range from minor annoyances to more significant problems that affect the vehicle’s performance and drivability.
Battery and Charging System Issues
The BMW 335i xDrive relies heavily on its electrical system to power various components, including the engine control module, sensors, and infotainment system. Some owners have reported issues with the battery and charging system, including premature battery failure and charging system faults.
A failing battery can lead to a variety of issues, including difficulty starting the vehicle, dimming lights, and malfunctioning electronics. If the battery is not holding a charge, it’s important to have it tested and replaced if necessary. Additionally, the alternator and voltage regulator should be inspected to ensure they are functioning correctly.
Sensor Failures
The BMW 335i xDrive 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 fail, leading to false warning lights on the dashboard or other issues.
One common issue is with the oxygen sensors, which monitor the oxygen levels in the exhaust gases. If an oxygen sensor fails, it can cause the engine to run too rich or too lean, leading to poor fuel economy, increased emissions, and potential damage to the catalytic converter.
Another issue is with the tire pressure monitoring system (TPMS), which can sometimes give false warnings about low tire pressure even when the tires are properly inflated. This can be due to a faulty sensor or a problem with the TPMS control module.
If you experience persistent warning lights or other symptoms related to sensor failures, it’s important 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 xDrive 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.
Suspension and Steering Issues
The BMW 335i xDrive F34 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 xDrive 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 xDrive. They connect the wheels to the chassis and allow the suspension to move up and down.
Some 335i xDrive 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 xDrive. 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 xDrive F34 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 xDrive F34 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 xDrive F34 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.
Conclusion
The BMW 3 Series F34 335i xDrive is a versatile and powerful vehicle that combines practicality with performance. However, like all cars, it has its share of common problems that owners should be aware of. By understanding these issues and addressing them promptly, you can maintain your vehicle’s performance and longevity, avoiding costly repairs and ensuring a smooth and enjoyable driving experience.
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, transmission issues, or any other concern, we’re here to help keep your BMW 335i xDrive running smoothly. Don’t hesitate to reach out to us for expert service and maintenance to ensure your BMW remains in top condition.
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