
2012 — 2016
3.5L V6 (M276) - SL350 BlueEFFICIENCY
Petrol
Check this by observing the transmission during your test drive: Pay attention to the 7G-TRONIC gearbox. On your drive, ensure the shifts are smooth without any hesitation or harsh 'clunking' between lower gears, as these units occasionally require a software update or fluid flush to maintain crisp performance.
While driving, listen for suspension noises: The R231 SL350 features a sophisticated suspension setup. Listen closely for any knocking or thumping over uneven road surfaces or speed bumps, as bushings and ball joints can show their age on New Zealand's varied road surfaces.
Check this by inspecting the vario-roof operation: Cycle the folding hardtop roof through a full open and closed sequence while the car is stationary on level ground. Watch for any jerky movements or warnings on the dash, as the hydraulic pumps and seals are complex and appreciate regular exercise.
While parked, inspect the electronics and COMAND system: Spend five minutes scrolling through the menus on the infotainment screen. Ensure all buttons are responsive and the Bluetooth/navigation systems connect properly, as intermittent software gremlins can occasionally crop up in aging premium electronic interfaces.
Consider a transmission fluid flush to maintain long-term gearbox health.
Usually the time to evaluate the state of the suspension control arms and bushes.
A major service interval where spark plug replacement and a full health check of the engine cooling system are recommended.
Ensure the engine oil and filter are changed every 10,000km or annually, whichever comes first.
Check the condition of the folding roof seals to ensure the interior stays dry during heavy NZ rainfall.
Verify the brake pads and discs have sufficient life, as these are premium components that work hard on a car of this weight.
Keep the battery healthy, as these cars are quite sensitive to voltage drops which can trigger false warning lights.
Inspect the M276 engine air filters to ensure the V6 can breathe freely for optimal efficiency.
Estimated repair costs if issues arise
If your SL is equipped with optional adaptive suspension, it is worth keeping in mind that these systems are complex. Depending on the car's history, you might eventually need to budget for sensor calibration or strut maintenance to keep the ride quality at its best.
To keep the roof folding smoothly, the hydraulic fluid may eventually need flushing or the cylinders might require a reseal. If this component needs attention in the future, it is a specialist job that ensures long-term roof reliability.
Over time, the rubber in the engine mounts can soften, leading to increased cabin vibration at idle. It is a common wear item for this engine configuration, and replacing them restores that signature Mercedes 'vault-like' stillness.
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Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer