2006 Mercedes-Benz R350
The 2006 Mercedes-Benz R350 is a luxury crossover/wagon that aimed to blend the comfort of a sedan with the practicality of an SUV. The R350 primarily came with a 3.5L V6 engine producing 268 horsepower and 258 lb-ft of torque, paired with a 7-speed automatic transmission (7G-TRONIC). Some owners appreciated its spacious interior, comfortable ride, and elegant styling. Common dislikes included the vehicle’s hefty size, potential for expensive repairs, and sometimes quirky electronics. Other engines include a 3.0L V6 diesel engine (R320 CDI) that produces 215 horsepower and 398 lb-ft of torque.
Engine
3.5L V6
- Balance Shaft Gear Wear
- Description/Symptoms: A common issue with the M272 engine (3.5L V6) involves premature wear of the balance shaft gear. This can cause rough running, misfires, and eventually a check engine light. The noise can be heard as a whine. Diagnostic trouble codes (DTCs) related to camshaft timing are often present.
- Solution: Replacement of the balance shaft, which is a labor-intensive job as it requires significant engine disassembly.
- Estimated Cost to Fix: $3,000 - $5,000+
- Recalls: None Found
- Intake Manifold Flap Motor Failure
- Description/Symptoms: The intake manifold on the M272 engine utilizes flaps to optimize airflow. The flap motor or the manifold itself can fail, resulting in reduced performance, poor fuel economy, and a check engine light.
- Solution: Replacement of the intake manifold assembly or the flap motor, depending on the specific failure.
- Estimated Cost to Fix: $800 - $1,500
- Recalls: None Found
3.0L V6 Diesel (R320 CDI)
- Oil Cooler Leaks
- Description/Symptoms: The oil cooler seal is prone to leaking. Leaking oil will drip onto the ground and potentially cause a burning smell.
- Solution: Replace the oil cooler seal
- Estimated Cost to Fix: $800 - $1,200
- Recalls: None Found
- Diesel Particulate Filter (DPF) Issues
- Description/Symptoms: DPF can become clogged over time, particularly with short trips or low-speed driving. This can lead to reduced performance, increased fuel consumption, and eventually a check engine light.
- Solution: Forced regeneration of the DPF, replacement of the DPF, or cleaning of the DPF (if possible).
- Estimated Cost to Fix: $300 - $2,000+ (depending on the solution)
- Recalls: None Found
Transmission
7G-TRONIC (722.9)
- Torque Converter Issues
- Description/Symptoms: Some owners have reported issues with the torque converter in the 7G-TRONIC transmission, leading to shuddering, hesitation during acceleration, or rough shifting.
- Solution: Replacement of the torque converter or, in some cases, a complete transmission rebuild.
- Estimated Cost to Fix: $1,500 - $4,000+
- Recalls: None Found
- Valve Body Problems
- Description/Symptoms: Malfunctioning valve bodies are another known issue in the 7G-TRONIC transmission. This can manifest as harsh shifting, delayed engagement, or failure to shift at all.
- Solution: Replacement or rebuilding of the valve body.
- Estimated Cost to Fix: $800 - $2,000
- Recalls: None Found
Suspension
- Air Suspension Failure (If Equipped)
- Description/Symptoms: The R350 can be equipped with Airmatic air suspension. The air struts can leak, leading to a sagging vehicle, particularly overnight. The air compressor can also fail. Dashboard warnings are usually present.
- Solution: Replacement of the leaking air struts or the air suspension compressor.
- Estimated Cost to Fix: $800 - $2,000+ per strut; $500 - $1,200 for the compressor.
- Recalls: None Found
- Rear Air Springs
- Description/Symptoms: Rear air springs may wear down over time. This can cause the rear of the vehicle to sag, especially when parked.
- Solution: Replacement of the air springs
- Estimated Cost to Fix: $600 - $1,000+
- Recalls: None Found
Electrical
- SAM (Signal Acquisition Module) Issues
- Description/Symptoms: The SAM controls various electrical functions. The front or rear SAM units can fail, leading to issues with lighting, wipers, power windows, and other electrical components.
- Solution: Replacement of the faulty SAM unit. Programming may be required.
- Estimated Cost to Fix: $500 - $1,500
- Recalls: None Found
- EIS (Electronic Ignition Switch) Failure
- Description/Symptoms: The EIS can fail, preventing the car from starting. This is a relatively common issue on Mercedes-Benz vehicles of this era.
- Solution: Replacement of the EIS and potentially reprogramming of the key.
- Estimated Cost to Fix: $800 - $1,800+
- Recalls: None Found
- Sunroof Motor Failure
- Description/Symptoms: The sunroof motor may fail or become weak, resulting in the sunroof not opening or closing properly.
- Solution: Replacement of the sunroof motor.
- Estimated Cost to Fix: $300 - $800
- Recalls: None Found
Exterior
- Tail Light Assembly Issues
- Description/Symptoms: The tail light assemblies can develop cracks, or the bulbs can frequently burn out due to electrical issues within the assembly.
- Solution: Replacement of the tail light assembly.
- Estimated Cost to Fix: $200 - $500 per assembly
- Recalls: None Found
Interior
- Command System Issues
- Description/Symptoms: Problems can arise with the COMAND system (Mercedes’ infotainment system), including screen failures, navigation malfunctions, or Bluetooth connectivity issues.
- Solution: Repair or replacement of the COMAND unit.
- Estimated Cost to Fix: $500 - $2,000+
- Recalls: None Found
Summary
The 2006 Mercedes-Benz R350, while offering luxury and practicality, is prone to several issues that can result in significant repair costs. Engine-related problems, particularly with the balance shaft on the 3.5L V6, and transmission issues with the 7G-TRONIC transmission, are common and expensive. Air suspension failures, if equipped, can also be costly. Electrical gremlins are also a common occurrence. Prospective buyers should be aware of these potential issues and budget accordingly, or seek a pre-purchase inspection by a qualified Mercedes-Benz mechanic. While maintenance costs can be high, addressing these issues proactively can help extend the life and enjoyment of the vehicle.