AI DamageMercedes-Benz 300SD: problems, complaints, bulletins
Summary for the Mercedes-Benz 300SD across 3 model years: 12 owner complaints and 0 NHTSA service bulletins, plus repair videos. Pick a year for details.
Model years
What fails most often
- 1 Electrical system 50% of all complaints
- 2 Engine and cooling 17% of all complaints
- 3 Tires 17% of all complaints
- 4 Service brakes 8% of all complaints
- 5 Steering 8% of all complaints
- 6 Vehicle speed control 8% of all complaints
- Electrical system: 6 complaints (50% of all).
- Engine and cooling: 2 complaints (17% of all).
- Tires: 2 complaints (17% of all), 1 of them with a crash reported by the owner.
- Service brakes: 1 complaints (8% of all).
- Steering: 1 complaints (8% of all).
Symptoms owners describe
How many of the 12 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) |
|---|---|---|---|
| Electrical system | 6 | 0 | 0 |
| Engine and cooling | 2 | 0 | 0 |
| Tires | 2 | 1 | 0 |
| Service brakes | 1 | 0 | 0 |
| Steering | 1 | 0 | 0 |
| Vehicle speed control | 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.
Was traveling about 65mph on highway and vehicle was shaking and vibrating. Also, lost control for a few monutes. He steered t vehicle to safety. Driver's rear tire tread separated.
Tl* the contact owns a 1993 mercedes-benz 300sd. The contact stated that the insulation had exposed and burnt wires. The contact called arlington mercedes-benz ([address], arlington, [ZIP], [phone]) and was informed that they no longer had parts for the vehicle. The vehicle was not diagnosed or repaired.
The engine wiring harness of my 1993 mercedes-benz 300sd has cracked insulation throughout and is beginning to short-circuit with the risk of causing dangerous engine malfunction and fire. I have read many reports of other mercedes-benz cars of the same age range 1992-1997 having the exact same defect "eco wiring".
It is a fire waiting to happen. There are many harness available for various models with the infamous "biodegradable" wiring problem. There are many different price ranges also, but they are available. As for the one that I need it is not available at any cost.
Tl* the contact owns a 1984 mercedes 300sd. The vehicle was equipped with goodyear assurance comforted 195/70/14 tires. Upon examining the vehicle, the contact noticed that the front passengers tire was deflated. The contact also stated that the sidewalls on all four tires were dry and rotted.
The car had 58,000 original miles on it. I was the second owner. I took the car to a local import car/mercedes service center to have it checked over. The mechanic pointed out that the main engine wiring harness and the glow plug wiring harness had serious problems.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
What to check before buying
- 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.
- Tires. Tire age by DOT code, bulges, wear pattern.
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
Other models of this make
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 2026-11-06.