2012 — 2020
4.7L V8 Twin-Turbo (M278) - SL 500
Petrol
With the roof down, listen closely for any rattles or creaks from the folding hardtop mechanism while driving over uneven road surfaces.
Check the air suspension by cycling through the vehicle's height settings while parked; ensure the car raises and lowers promptly without warning lights on the dash.
Gently accelerate on a clear stretch of road to check for any hesitations or surging, which might indicate the health of the twin-turbo system's vacuum lines or ignition coils.
Before starting the engine from cold, inspect the engine bay for any faint scent of coolant or oil residue near the V-valley, as this can be a sign of early seepage.
Usually when spark plugs and transmission fluid services are recommended to maintain that V8 smoothness.
A common window where engine mounts may begin to show signs of age, which might be felt as slight vibrations at idle.
Often the time to inspect the auxiliary systems and the health of the ABC or air suspension compressors.
Keep up with the strict oil change intervals using high-quality synthetic lubricants to protect those twin turbochargers.
Regularly clear out the cabin and sunroof drainage points to ensure moisture doesn't find its way into the electronics.
Keep the roof mechanism lubed and clean; a little bit of preventative maintenance goes a long way for those complex moving parts.
Ensure the transmission software is updated during service visits to keep the gear changes feeling crisp and responsive.
Check the battery health periodically, as these R231 models are quite sensitive to voltage drops and can throw phantom codes if the battery is tired.
Estimated repair costs if issues arise
If the vehicle sits unevenly after being parked for a few days, you might eventually need to budget for strut replacement, which involves replacing the pneumatic components.
In some M278 engines of this generation, it is common to consider checking the chain tensioners during major services to ensure long-term timing system health.
Depending on the car's history, if you notice a subtle vibration while sitting at traffic lights, you might eventually need to budget for a refresh of the mounts to restore that factory-fresh smoothness.
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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