2010 Mercedes-Benz SL 3.5L Petrol · B11 OBD

A pattern of corrosion-related advisories concentrated on the nearside suspension and braking components defines the mechanical history of this 2010 Mercedes-Benz SL, with the most recent pass on 29 October 2025 recording only tyre wear as a concern. The earlier 2024 test cycle is more revealing: a fail on 9 October 2024 was followed by a pass just seven days later on 16 October 2024, with both tests carrying identical advisories for a corroded nearside front brake pipe, a pitted nearside front inner brake disc with a slight lip, a corroded nearside rear coil spring, a discoloured nearside rear direction indicator, and a defective nearside rear exhaust mounting. The complete absence of any recorded defects at the 2022 and 2023 tests suggests the corrosion progression is relatively recent rather than chronic, but the clustering of multiple advisories on one side of the vehicle within a single annual cycle points to localised exposure conditions or a delayed maintenance interval catching up with the car simultaneously. The 2025 pass without any carry-over of those earlier items indicates remedial work was carried out, though brake pipe corrosion in particular tends to recur if the surrounding underbody protection has not been addressed. The recorded mileage of 80,352 miles across sixteen years equates to an annual accumulation of roughly 5,022 miles, which is notably low for a vehicle of this age and profile. While low annual mileage reduces wear on major drivetrain components such as the engine, transmission, and main bearings, it brings its own mechanical considerations for an SL. Extended standing periods allow moisture to settle on brake discs, promote corrosion on exposed metal components such as the brake pipes and coil springs already flagged in the history, and can lead to dried seals in the hydraulic system and roof mechanism. The fact that the MOT history shows consistent annual testing from 2022 onwards suggests the vehicle has been kept in regular use rather than laid up, which is favourable, but the sudden appearance of multiple corrosion advisories in 2024 after clean tests in 2022 and 2023 demonstrates how quickly surface degradation can develop once protective coatings begin to fail. For a prospective buyer, the nearside front brake pipe and nearside rear coil spring corrosion should be the priority inspection items, as these are the components most likely to progress between MOT tests and were flagged on the same side within a short window. On a test drive, listen for any clonking or knocking from the rear suspension over uneven surfaces, which could indicate the corroded coil spring has begun to fracture or that associated bushes have hardened; the SL's multi-link rear suspension is particularly sensitive to bush deterioration, so any vagueness in rear wheel location or trampiness over bumps warrants further investigation. The brake pedal should feel firm and progressive, with no sponginess suggesting compromised pipe integrity, and there should be no pulling to one side under braking, which could indicate the pitted nearside front disc has worn unevenly or that a caliper slide pin is binding. The defective exhaust mounting flagged in 2024 should be confirmed as resolved by physically inspecting the nearside rear hanger for security and checking for any exhaust movement when the car is started from cold. Additional checks specific to this vehicle's recorded history include a close visual inspection of the nearside front tyre and nearside rear tyre for uneven shoulder wear, as the 2025 advisory noted both were worn close to the legal limit and on the edge, which on a rear-wheel-drive SL could point to misalignment, worn suspension geometry, or incorrect inflation. The slightly discoloured nearside rear direction indicator should be examined for correct operation and lens condition, as discolouration can indicate heat damage to the bulb holder or socket. Given the low annual mileage and the Mercedes-Benz SL's known sensitivity to prolonged standing, the buyer should also verify the operation of the hydraulic folding roof mechanism through a full open and close cycle, confirm the air suspension or ABC system (if fitted) operates without warning messages, and check for any oil leaks from the engine and rear differential, as these are common areas where seals deteriorate with age rather than with mileage. A thorough underbody inspection by a specialist familiar with the R230 chassis is strongly recommended to confirm the corrosion advisories were fully rectified rather than merely cosmetically treated.