If you are considering buying a used Mercedes-Benz SL, these are the common problems worth knowing about first. Our garage database tracks 4 known faults for this model, 3 of them rated high severity. Every one below is a repair bill a seller has good reason not to mention.
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Check a Mercedes-Benz SL advert (free) →The Mercedes-Benz SL has 4 known faults in our database, 3 of them rated high severity. The most serious are bodywork (water leaks into the boot are common. The seal at the rear of the folding roof is poorly) and suspension (the Active Body Control hydraulic suspension is expensive when it goes wrong). None of them makes the car a bad buy on its own; the risk is a seller who knows and says nothing.
That is a count of the faults we hold, not a reliability score. Popular cars get written about more, and a newer generation has had less time to show its faults.
No year is a write-off on its own. What matters is which serious faults a given year and engine can have, and whether the car in front of you has had them fixed.
Each one is set out in full below, with the symptoms, the typical mileage and a rough repair cost.
One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.
One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.
Sellers rarely admit these faults outright
We track 12 specific phrases sellers use in adverts to soft-pedal these exact issues. Paste any Mercedes-Benz SL advert and we check it in seconds.
Check an advert now (free) →Recall work is done by the manufacturer, and GOV.UK says you will not usually have to pay for it. These are the 16 DVSA recalls for the SL, newest first. They do not tell you whether this particular car has had the work: for that, put the registration into the free GOV.UK MOT history check, which shows a recall status where the manufacturer shares it, or ask a franchised dealer to check the VIN.
Mercedes-Benz has determined that on certain AMG GT Coupe (192 platform)S-Class (223 platform) SL (232 platform) GLC (254 platform) and AMG GT 4-doorsCoupe (290 platform) vehicles with hybrid powertrain the processor of the control unit of the high-voltage starter generator might experience sporadic overload.
Put right by: As a remedy Mercedes-Benz AG via its Mercedes-Benz service partners will update the software of the high-voltage starter generator on the affected vehicles.
On certain vehicles some 80A fuses installed might not meet requirements.
Put right by: Replace the respective main fuse boxes on the affected vehicles.
On affected vehicles the 12V-starter / generator wiring harness might not meet specifications.
Put right by: Rework the routing of the wiring harness.
On affected vehicles the fuel pump impeller might not meet specifications and may deform.
Put right by: Replace the fuel pump module.
The software of the communication module may not correspond with the specifications.
Put right by: Update the software of the communication module in the affected vehicles.
The bolting connections of the driver and passenger seat rail and the body shell might not meet the requirements.
Put right by: Rework the bolt connection between the seat rail and the body shell.
The hands-off detection might not detect when the driver's hands are away from the steering wheel.
Put right by: Update the coding of the hand detection system on the affected vehicles.
On certain vehicles the software of the communication module might not meet specifications.
Put right by: As a precautionary measure update the software of the communication module on the affected vehicles. This software update is planned to be performed over-the-air with no workshop visit being required.
The behaviour of the emergency call system might not meet specifications.
Put right by: Update the software of the communication module for the emergency call system.
The behaviour of the emergency call system might not meet specifications.
Put right by: Update the software of the communication module for the emergency call system.
The behaviour of the emergency call system might not meet specifications.
Put right by: Update the software of the communication module for the emergency call system.
The behaviour of the emergency call system might not meet specifications.
Put right by: Update the software of the communication module for the emergency call system.
The software of certain communication modules may not meet specifications.
Put right by: Carry out an update to the software of the communication module on affected vehicles.
On affected vehicles the software of the communication module for the emergency call system does not meet the specification
Put right by: Update the software of the communication module for the emergency call system
The refrigerant used in the air conditioning system does not meet legal requirements
Put right by: The air conditioning system will be adapted for the usage of the new refrigerant.
The refrigerant used in the air conditioning system does not meet legal requirements.
Put right by: The air conditioning system will be adapted for the usage of the new refrigerant.
Recall data published by the Driver and Vehicle Standards Agency under the Open Government Licence v3.0. A recall listed here may not apply to every car of this model: the build dates and the registration check are what decide it.
Three stand out. Bodywork: water leaks into the boot are common. The seal at the rear of the folding roof is poorly designed. Suspension: the Active Body Control hydraulic suspension is expensive when it goes wrong (typically 20000 to 55000 miles). Brakes: sensotronic Brake Control (SBC) pump reaches its pre-programmed actuation limit and fails (typically 80000 to 150000 miles). The full list above is grouped by generation, with typical mileage and a rough repair cost for each.
No Mercedes-Benz SL year is a write-off, but the R230 (2002 to 2011) carries the most serious faults: bodywork, suspension and brakes. Year matters less than whether the specific car has had the known fixes, so check the history for them.
Ask the seller about the bodywork, suspension and brakes faults on this page and whether they have been fixed, with invoices. On the test drive watch for damp or standing water in the boot well and spare wheel area, ABC visit workshop warning, white or red and white 'Service Brake - Visit Workshop' warning. Read the MOT history for repeat advisories, then paste the advert into the free check, which reads it against all 4 known faults before you travel. Check a Mercedes-Benz SL advert →
The DVSA lists 16 safety recalls for the Mercedes-Benz SL issued between 2019 and 2025. The most recent, from April 2025, is "SRPC2501 - Processor Starter/Generator". Recall work is done by the manufacturer, and GOV.UK says you will not usually have to pay for it. This list is by model, so it cannot tell you whether one particular car has had the work: the free GOV.UK MOT history check shows a recall status from the registration where the manufacturer shares it, and a franchised dealer can check the VIN.
Owners report 26.6 mpg on average across the Mercedes-Benz SL engines with data, about 92% of the official combined figure. The gap between official and real-world economy varies a lot by engine, so the Real MPG page lists every engine and generation separately, from 83 owner submissions. Mercedes-Benz SL Real MPG by engine →
Looking at a Mercedes-Benz SL right now? Check the advert before you go and see it.
If you used to check the Honest John “Good & Bad” section before the site closed in 2026, this page is where that information now lives. We rebuilt the Mercedes-Benz SL owner-report history from the archived Honest John dataset, added our own research, specialist and owner-club sources and DVSA recall data, and we keep it free. Each fault above is badged with its source. The same data feeds our free advert check, which reads a listing against every known fault for the exact engine and year.
CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services. What happened to Honest John, and where each feature lives now.
Knowing what a Mercedes-Benz SL goes wrong with is half of it. The rest is reading the advert and checking the car's history before you hand any money over.