Purchasing a classic Mercedes-Benz SL500 is often a dream for car enthusiasts. The 2001 model, part of the R129 generation, holds a special appeal with its blend of luxury and performance. However, like any vehicle, especially one of this age, potential buyers should be aware of potential issues. This article delves into the real-world ownership experience of a 2001 Mercedes Sl500, highlighting common problems and maintenance concerns based on an owner’s detailed account.
One of the initial issues encountered was related to engine performance. The owner reported a prolonged engine cranking time and an erratic idle, suggesting underlying problems. This was eventually traced back to a failing Crankshaft Position Sensor (CPS). A faulty CPS can lead to starting difficulties and rough engine running, and in this case, it even caused a breakdown. Attempts to resolve the rough idle with standard maintenance like new spark plugs, wires, and induction cleaning proved ineffective, emphasizing the importance of accurate diagnosis.
Alt text: Front view of a 2001 Mercedes-Benz SL500 R129 showcasing its iconic roadster design.
Convertible top issues are also mentioned, specifically the failure of the two front top locks. These mechanisms are crucial for securing the convertible top and ensuring a weather-tight seal. Replacement of these locks indicates a potential wear point in the R129 SL500’s convertible system.
Fuel delivery problems surfaced with a noisy fuel pump that required replacement at a relatively low mileage of 45,000 miles. An early fuel pump failure can disrupt fuel supply to the engine, leading to performance issues or even engine stalling.
The 2001 SL500, being a technologically advanced car for its time, also experienced issues with its Tele-Aid system. Numerous failures rendered the concierge and navigation features unusable, as communication was impaired. Furthermore, the audio system exhibited disruptive behavior, with loud beeps, static, and screeching noises interrupting radio playback. This issue was so severe it necessitated pulling over the vehicle. The inability to adjust the Tele-Aid volume compounded the problem.
An unusual electrical anomaly was the power antenna operating erratically, extending and retracting even when the car was parked in a garage. This seemingly minor issue can point to underlying electrical gremlins within the vehicle’s systems.
More significantly, the car suffered from complete electrical shutdowns while driving. This serious problem was temporarily resolved by making a phone call, oddly enough, suggesting a link to the outdated analog phone system. Ultimately, replacing the analog phone and Tele-Aid systems with digital counterparts rectified both the Tele-Aid issues and the electrical power failures. This highlights the challenges of maintaining older vehicles with outdated technology and the potential need for system upgrades.
Alt text: Interior view of a 2001 Mercedes-Benz SL500 R129 dashboard highlighting the classic Mercedes design and technology features.
Mechanical issues were also prominent. A rear main seal leak necessitated replacement, a repair that involves separating the engine and transmission, indicating a significant undertaking. Another major failure involved the park shift lock cable assembly. Its failure led to a complete loss of transmission fluid, resulting in a second breakdown. This incident underscores the importance of transmission maintenance and the potential consequences of component failure.
Braking performance was consistently described as unsatisfactory, with excessive pedal travel. Despite replacing all brake components – calipers, rotors, pads – and bleeding the fluid multiple times, the issue persisted. The owner was considering master cylinder replacement to finally address the brake feel, demonstrating the complexity of diagnosing and resolving braking system problems even with comprehensive parts replacement.
Transmission shifting problems were eventually diagnosed and resolved by a different dealership. The issue was traced to transmission fluid leaking into the control unit located under the passenger footwell. This fluid intrusion into the control unit, via the wiring harness, caused the transmission’s electronic brain to malfunction. Replacing the control unit and addressing the fluid leak dramatically improved the car’s shifting performance and even minimized the erratic idle. The owner’s advice to check for transmission fluid in the passenger footwell is a crucial tip for potential R129 SL500 owners.
Further maintenance included replacing engine and transmission mounts, as well as strut mounts. These components are subject to wear and tear over time and are essential for maintaining vehicle stability and ride comfort.
Vibrations were addressed by rebuilding all four wheels and fitting new tires. The R129 chassis is known for transmitting feedback to the driver, which can amplify any imbalances in the wheels or tires. Replacing both front wheel bearings was also necessary to eliminate noise and ensure smooth wheel rotation.
Alt text: Detailed view of a 2001 Mercedes-Benz SL500 R129 engine bay showcasing the V8 engine and surrounding components.
Despite these numerous problems, the owner expresses a continued loyalty to the Mercedes-Benz brand and the SL model in particular. The appeal of the SL’s design, size, and unique category outweighs the negative ownership experience to some extent. However, the repeated failures and significant maintenance costs have understandably caused hesitation about future Mercedes purchases, particularly models with similar engine and transmission configurations.
For anyone considering a 1999 to 2002 Mercedes SL500 (R129), this owner’s experience serves as a valuable cautionary tale. Prospective buyers should be particularly vigilant about the transmission issues, a known vulnerability that can be expensive to repair. Ensuring that the digital upgrade for the Tele-Aid system has been performed is also advisable. While the 2001 SL500 can offer a rewarding driving experience after addressing these issues, potential owners must be prepared for the possibility of significant maintenance and repair costs associated with a vehicle of this age and complexity. Thorough pre-purchase inspections and a detailed service history are essential when considering a 2001 Mercedes SL500.
