AI Damage2003 Mercedes-Benz SL Class: common problems
Owners of the 2003 Mercedes-Benz SL Class filed 9 complaints with NHTSA, most often about service brakes and electrical system. Details by component below, with sources.
Key figures
- Owner complaints
- 9
- involving a crash
- 1
What fails most often
- 1 Service brakes 33% of all complaints
- 2 Electrical system 22% of all complaints
- 3 Engine and cooling 22% of all complaints
- 4 Structure 22% of all complaints
- 5 Suspension 22% of all complaints
- 6 Visibility 22% of all complaints
- 7 Air bags 11% of all complaints
- 8 Backover prevention 11% of all complaints
- Service brakes: 3 complaints (33% of all).
- Electrical system: 2 complaints (22% of all).
- Engine and cooling: 2 complaints (22% of all), 1 of them with a crash reported by the owner.
- Structure: 2 complaints (22% of all).
- Suspension: 2 complaints (22% of all).
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 5 L · petrol · 8 cyl
- 5.5 L · petrol · turbo · 8 cyl
- automatic, 5-speed
Drive: RWD
Symptoms owners describe
How many of the 9 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Service brakes | 3 | 0 | 0 |
| Electrical system | 2 | 0 | 0 |
| Engine and cooling | 2 | 1 | 0 |
| Structure | 2 | 0 | 0 |
| Suspension | 2 | 0 | 0 |
| Visibility | 2 | 0 | 0 |
| Air bags | 1 | 0 | 0 |
| Backover prevention | 1 | 0 | 0 |
| Exterior lighting | 1 | 0 | 0 |
| Fuel system | 1 | 0 | 0 |
| Powertrain | 1 | 0 | 0 |
| Tires | 1 | 0 | 0 |
| Vehicle speed control | 1 | 1 | 0 |
| Other | 1 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
2003 mercedes benz slk 320 experiencing problems with hesitation when the accelerator is depressed. On one occasions when the consumer attempted to apply the gas the vehicle did not move for a few seconds and then all of a sudden the vehicle lurched forward and the consumer hit another vehicle.
The new extended warranty on this brake failure issue was for complete parts and labor. I was never notified of this extended warranty. No one at the dealership, where I have had the car serviced exclusively, notified me of any warranty extension for this very serious braking failure issue. I find this reprehensible!
No incident. Was driving and as I pulled into my driveway, heard bumping sound from car. Asked mercedes what it was, they said loose baffle in gas tank. Sounds like manufacturing defect. Checked online and found many others with same problem. It is a costly repair just outside of warranty period.
As of today 8 november 2005, the suspension apparently can not be repaired. The car has being taken back to the dealer for the eight (8th) time to repair the suspension. It is currently alexandria virginia, mercedes benz as of november 9th, 2005.
I turned key and car did not start. I ended up getting stuck either at home or in a shopping center. Car had to be put on a flat bed. Dealer relpaced parts each time , but could not find the cause of the problem.
The vehicle (2003 mb slk320) was purchased on 4/14/2004 in az and began noticing problems on the drive back to nm. The most significant safety problem involves the transmission, which has been serviced by the manufacturer 8 times without resolution. The vehicle slips in and out of gear at highway speeds.
Hydraulic brake failure, totally unexpected. Car is a marcedes benz sl500, 2003. Only 8,500 k. On 6-24-04, mb issued a safety bulletin (nhtsa campaign id no. 04v296000)mb has not notified owners like me. I run a 4-way stop sign and a large pick-up truck was within 1 or 2 feet from hitting me on the drivers' side.
In the right door panel there is a glue that seals the panels together. This glue gives off toxic fumes. Consumer's wife is currently seeing a neurologist for problems suffered from inhaling the fumes. The manufacturer and the dealer have been notified.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 11,366 of 36,656 model years in the NHTSA data (top 31% most complained about).
On average one model year of the SL Class has 4 complaints (7 years in the data). This year has 9, above average.
What to check before buying
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Engine and cooling. Radiator and fan after a frontal hit, coolant level and condition, overheating.
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
Other years of this model
Questions and answers
What are the most common problems with the 2003 Mercedes-Benz SL Class?
Owner complaints to NHTSA most often mention: service brakes, electrical system, engine and cooling. Total complaints: 9. The most frequent symptoms in complaint texts: brake failure (22%), A/C or heater (11%), hesitation when accelerating (11%).
How many service bulletins (TSB) were issued for the 2003 Mercedes-Benz SL Class?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2003 Mercedes-Benz SL Class from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2003 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.