Mercedes-Benz A 220 d
Widely used Mercedes diesel with aluminium block and steel liner. High mileages possible but known for injector seal issues, timing chain stretch and EGR problems.
Diesel minimum
Only 125 kW diesel in a compact. Economical yes, fun no.
Engine Weaknesses 6
Over 100,000 vehicles recalled: the chain tensioner seal leaks, allowing engine oil to drip onto the exhaust system and potentially ignite.
Symptoms: Dropping oil level, oil smell from engine bay, oily deposits under the vehicle, possible oil fire
The OM651 uses a simplex timing chain. With short-trip driving and overdue oil change intervals the chain stretches.
Symptoms: Light rattling noise on cold start from the rear of the engine, no fault code stored
Same Delphi piezo injector problems as in the DE18: 220 CDI and 250 CDI variants affected. Mercedes replaced them with solenoid injectors as part of a service action.
Symptoms: Vibrations and rough running especially under acceleration, elevated fuel consumption
The EGR cooler of the OM651 develops hairline cracks at the connection stub and loses coolant. Green staining next to the fuel filter under the engine cover is typical.
Symptoms: Dropping coolant level without visible leak, intermittent coolant warning, green spots under the vehicle, heater output diminishing
The DMF on the OM651 suffers under the high torque output. Documented case: all 8mm rivets sheared at 149,000 km, with consequential damage to the clutch and crankshaft speed sensor.
Symptoms: Rattling and juddering at warm idle, vibrations when pulling away, shuddering at low RPM, noise increases with warm engine
From around 150,000–180,000 km the OM651 turbocharger leaks oil through worn bearings, which drips onto the EKAS intake port deactivation actuator and destroys it. Double damage.
Symptoms: Black smoke under acceleration, oil residue in charge air hose, power loss, fault code P0299 boost pressure underrun
Vehicle Weaknesses 7
Recall due to defective windscreen bonding. In an accident the screen may detach and occupant protection cannot be guaranteed. Affects vehicles up to July 2013.
7G-DCT judders when pulling away and during shifts 1–3, especially during the cold warm-up phase. Software updates often help but do not always solve the problem permanently. Clutch wear increased in urban traffic.
Xenon headlights of early model years permanently mist up internally. A complete xenon headlight costs over €1,000. LED headlights of facelift models (from autumn 2015) significantly more robust.
Certain condenser batch has defective welds and loses refrigerant. Replacement costs €1,200 including labour. Recall for A/C as fire risk known.
Early infotainment system (COMAND) of pre-facelift version freezes, starts slowly or crashes. Collision warning PRE-SAFE triggers false emergency braking. Software updates required.
According to MOT reports, indicators and hazard warning lights fail more than average on the W176. Defective relays or control units are usually the cause.
Plastic trim panels in the interior, panoramic roof and boot cover produce annoying creaking and rattling noises. Cheap interior for the brand's level is a common criticism.