2015 BMW Z4
The 2015 BMW Z4 is a stylish and sporty two-seat convertible roadster. The 2015 Z4 came with three engine options: the sDrive28i which is a 2.0-liter turbocharged inline-4 producing 240 horsepower and 260 lb-ft of torque, the sDrive35i with a 3.0-liter turbocharged inline-6 producing 300 horsepower and 300 lb-ft of torque, and the sDrive35is with a tuned version of the 3.0-liter turbocharged inline-6 producing 335 horsepower and 332 lb-ft of torque. The sDrive28i could be paired with either a 6-speed manual or an 8-speed automatic transmission, while the sDrive35i offered a 6-speed manual or a 7-speed dual-clutch automatic transmission. The sDrive35is was only available with the 7-speed dual-clutch automatic. Many owners praise the Z4 for its sleek design, engaging driving dynamics, and comfortable interior for a roadster. Common complaints include a relatively small trunk, limited storage space in the cabin, and potential for expensive repairs due to the car’s complexity.
Engine
2.0L Turbocharged Inline-4 (sDrive28i)
- Oil Leaks
- Description/Symptoms: Oil leaks can develop from various points on the engine, including the valve cover gasket, oil filter housing, and oil pan gasket. Symptoms include visible oil leaks, burning oil smell, and low oil level.
- Solution: Replacing the leaking gasket or component is the solution. For more severe leaks, inspecting the oil system components, such as the oil pump and lines, and replacing any damaged parts is necessary.
- Estimated Cost to Fix: $150 - $1,000+ depending on the source of the leak.
- Recalls: None Found
3.0L Turbocharged Inline-6 (sDrive35i & sDrive35is)
- High Pressure Fuel Pump (HPFP) Failure
- Description/Symptoms: The High Pressure Fuel Pump is a common issue with the N54 and N55 engines. Symptoms include extended cranking, long start times, rough idling, hesitation during acceleration, and potential engine stalling. Diagnostic trouble codes (DTCs) related to fuel pressure will likely be stored in the ECU.
- Solution: Replacement of the HPFP is the typical solution.
- Estimated Cost to Fix: $800 - $1,500+
- Recalls: None Found
- Oil Filter Housing Gasket Leak
- Description/Symptoms: The oil filter housing gasket can leak, causing oil to drip onto other engine components. This can lead to a burning oil smell and low oil level.
- Solution: Replace the oil filter housing gasket.
- Estimated Cost to Fix: $300 - $600
- Recalls: None Found
Transmission
8-Speed Automatic (sDrive28i)
- Rough Shifting/Hesitation
- Description/Symptoms: Some owners report experiencing rough or delayed shifts, especially when the transmission is cold. Hesitation during acceleration can also occur.
- Solution: In some cases, a software update can resolve the issue. For more severe cases, valve body replacement or a transmission rebuild might be necessary.
- Estimated Cost to Fix: $200 (software) - $4,000+ (rebuild)
- Recalls: None Found
7-Speed Dual-Clutch Automatic (sDrive35i & sDrive35is)
- Clutch Wear/Failure
- Description/Symptoms: Due to the complexity of the dual-clutch transmission, clutch wear can occur. This is exacerbated by aggressive driving or frequent stop-and-go traffic. Symptoms include slipping, jerky engagement, and difficulty shifting.
- Solution: Replacing the clutch packs is the typical solution.
- Estimated Cost to Fix: $3,000 - $6,000+
- Recalls: None Found
Suspension
- Adaptive M Suspension Issues (If Equipped)
- Description/Symptoms: The adaptive dampers can fail, leading to a stiff or bouncy ride. Error messages related to the suspension system might appear on the instrument cluster.
- Solution: Replacement of the faulty damper(s) is required.
- Estimated Cost to Fix: $800 - $1,500+ per damper
- Recalls: None Found
- Control Arm Bushing Wear
- Description/Symptoms: The control arm bushings can wear out, leading to vibrations, clunking noises, and imprecise handling.
- Solution: Replacing the worn control arm bushings.
- Estimated Cost to Fix: $300 - $800 per control arm
- Recalls: None Found
Electrical
- Battery Drain
- Description/Symptoms: Some owners have reported issues with excessive battery drain, especially when the car is not driven frequently. This can lead to difficulty starting the car or a completely dead battery.
- Solution: Troubleshooting the electrical system to identify the source of the drain and replacing the faulty component. Common culprits include the comfort access system, faulty modules, or aftermarket accessories.
- Estimated Cost to Fix: $100 - $1,000+ depending on the source of the drain.
- Recalls: None Found
- Convertible Top Malfunctions
- Description/Symptoms: The convertible top mechanism can experience malfunctions, such as getting stuck, making unusual noises, or failing to operate altogether.
- Solution: Diagnosing the fault, which may involve hydraulic pump failure, sensor issues, or damage to the mechanical components.
- Estimated Cost to Fix: $500 - $2,000+
- Recalls: None Found
Exterior
- No Issues Found
Interior
- No Issues Found
Summary
The 2015 BMW Z4, while a desirable sports car, presents some common issues owners should be aware of. Engine-related problems, such as oil leaks and HPFP failure, can be costly to repair. Transmission issues, especially with the dual-clutch transmission, can also lead to significant expenses. Suspension and electrical problems can further add to the ownership costs. Overall, potential buyers should have a pre-purchase inspection performed to identify any existing or potential issues and factor in the cost of potential repairs when considering a 2015 Z4. The severity of the issues varies, but costs can range from a few hundred dollars for minor fixes to several thousand for major repairs like transmission or HPFP replacement.