Models · Mercedes-Benz
Mercedes-Benz SL R129 buying guide
The R129 SL was built from 1989 to 2001 with a power-operated soft top and a removable hardtop, and engines ranging from straight sixes to a V12. Most of its known faults show at a careful viewing.
The versions
- Straight six: 300SL and 300SL-24 (M103 and M104), then SL280 and SL320 (M104, 193hp and 231hp) from 1993
- V6 from 1998: SL280 and SL320 (M112, 204hp and 224hp)
- V8: 500SL/SL500 with the M119 5.0 litre (320 to 326hp), then the M113 5.0 litre (306hp) from 1998
- V12: 600SL/SL600 with the M120 6.0 litre, 394hp; rare AMG SL60 and SL73 versions
- Four-speed automatic, five-speed automatics (722.5, then 722.6 from 1996) and a five-speed manual
What to check on a R129 SL
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
The hood and hardtop
What to look for: Operate the soft top fully up and down at least twice. It should move smoothly without stalling. Look along the front header rail and around the hood mechanism for hydraulic fluid leaks, and check the plastic rear window for splits where it folds.
Why it matters: The hood is hydraulic, and leaks show up at the header rail. The roof controller module, under the rear seat, can play up with age, and jump-starting the car can shorten its life. A hood that cycles cleanly is a good sign.
Engine bay wiring on 1993 to 1995 cars
What to look for: On a 1993 to 1995 car, look at the wiring in the engine bay for cracked or crumbling insulation, and ask whether the engine wiring harness has been replaced. On the drive, feel for misfires or hesitation.
Why it matters: Cars from 1993 to 1995 suffer from the engine wiring harness degrading. On the M104 straight sixes, crumbly wiring looms and damp distributor caps are a known cause of misfires. A replaced harness is a sign of a car that's been looked after.
Tappety noise and cam oilers on the M119 V8
What to look for: On an early V8 (M119, before 1998), listen to the top of the engine at idle and as it warms for a tappety or rattly noise. Ask whether the cam oil feed pipes have been replaced.
Why it matters: Tappety noise on the M119 is usually failed plastic cam oil feed pipes, which can block and spoil the running. Replacing all of them puts it right. The M119's timing chain is good for about 150,000 miles, so ask about it on high-mileage cars.
Also in the full guide
- The automatic gearbox
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the R129 SL
The CrankSight guide walks you round the car on your phone at the viewing, with every check for the exact version you're looking at: what to look for, where to find it, and what anything you find is likely to cost. As you go it builds an assessment of that car, and if you view more than one, it lines them up side by side.
£29 for the model, used on as many cars as you like, delivered within 72 hours or your money back.
Other generations
General points for the model, last checked October 2026. Every car is different, so treat this as a guide to what to look at, not a verdict on any car. CrankSight is independent and has no connection with Mercedes-Benz.