Mercedes-Benz A-Klasse W169
Weaknesses, engine ratings and buying advice
Generations
Engine Overview
The Mercedes-Benz A-Klasse W169 is available with 7 engine variants — from 82 to 193 hp.
Robust two-litre diesel with common rail. Known for leaking injector seals and DPF issues under short-trip use. Otherwise long-lived.
- !! Injectors Leaking — Tar Deposits and Pressure Loss from 150,000 km
The OM640 injectors loosen and develop leaks in service. From approximately 150,000 km, tarry gases enter the engine bay and the cabin. All injectors should be replaced simultaneously.
Symptoms: Knocking 'psch-psch-psch' noise, engine warning light, soot deposits around injectors, misfires, diesel smell in the cabin - !! Timing Chain Rattles — Chain Tensioner Worn from 160,000 km
The OM640 shows metallic rattling at cold start from approximately 150,000 km due to timing chain stretch. Complex removal as the engine in the W169/W245 is mounted at an angle and must be lowered.
Symptoms: Metallic rattling at cold start, noise fades when warm, knocking on load changes, CEL possible - !! EGR Valve Coked Up and Stuck from 100,000 km
The EGR valve on the OM640 tends to coke up with soot deposits, particularly during frequent short-trip use. A stuck EGR valve significantly worsens performance and fuel economy.
Symptoms: Poor throttle response, elevated fuel consumption, engine warning light, rough idle, soot clouds under acceleration
+ 3 more engine weaknesses + vehicle weaknesses
Robust two-litre diesel with common rail. Known for leaking injector seals and DPF issues under short-trip use. Otherwise long-lived.
- !! Injectors Leaking — Tar Deposits and Pressure Loss from 150,000 km
The OM640 injectors loosen and develop leaks in service. From approximately 150,000 km, tarry gases enter the engine bay and the cabin. All injectors should be replaced simultaneously.
Symptoms: Knocking 'psch-psch-psch' noise, engine warning light, soot deposits around injectors, misfires, diesel smell in the cabin - !! Timing Chain Rattles — Chain Tensioner Worn from 160,000 km
The OM640 shows metallic rattling at cold start from approximately 150,000 km due to timing chain stretch. Complex removal as the engine in the W169/W245 is mounted at an angle and must be lowered.
Symptoms: Metallic rattling at cold start, noise fades when warm, knocking on load changes, CEL possible - !! EGR Valve Coked Up and Stuck from 100,000 km
The EGR valve on the OM640 tends to coke up with soot deposits, particularly during frequent short-trip use. A stuck EGR valve significantly worsens performance and fuel economy.
Symptoms: Poor throttle response, elevated fuel consumption, engine warning light, rough idle, soot clouds under acceleration
+ 3 more engine weaknesses + vehicle weaknesses
Robust two-litre diesel with common rail. Known for leaking injector seals and DPF issues under short-trip use. Otherwise long-lived.
- !! Injectors Leaking — Tar Deposits and Pressure Loss from 150,000 km
The OM640 injectors loosen and develop leaks in service. From approximately 150,000 km, tarry gases enter the engine bay and the cabin. All injectors should be replaced simultaneously.
Symptoms: Knocking 'psch-psch-psch' noise, engine warning light, soot deposits around injectors, misfires, diesel smell in the cabin - !! Timing Chain Rattles — Chain Tensioner Worn from 160,000 km
The OM640 shows metallic rattling at cold start from approximately 150,000 km due to timing chain stretch. Complex removal as the engine in the W169/W245 is mounted at an angle and must be lowered.
Symptoms: Metallic rattling at cold start, noise fades when warm, knocking on load changes, CEL possible - !! EGR Valve Coked Up and Stuck from 100,000 km
The EGR valve on the OM640 tends to coke up with soot deposits, particularly during frequent short-trip use. A stuck EGR valve significantly worsens performance and fuel economy.
Symptoms: Poor throttle response, elevated fuel consumption, engine warning light, rough idle, soot clouds under acceleration
+ 3 more engine weaknesses + vehicle weaknesses
Development of the M166 with CVT option. Turbo variant (200 Turbo) powerful but rare. Solid everyday engines with few typical failures.
- !! CVT Gearbox Loses Drive from 130,000 km
The Autotronic CVT (722.8) on the M266 is failure-prone: the push belt wears or the output speed sensor in the control unit fails. When faulty, only engine rpm rises on acceleration with no drive.
Symptoms: Engine revs climb, vehicle does not accelerate, CVT warning on display, no drive in D or R - !! Defective Gearbox Control Unit — Fault Codes P0706 / 0722 from 120,000 km
The CVT gearbox control unit develops faults in the internal speed sensor. Typical fault codes are P0706 and 0722/0723. New control unit requires manufacturer programming and is expensive.
Symptoms: Fault message 'Transmission — visit workshop', jerky shifting, vehicle stranding, gearbox limp mode - !! CVT Autotronic — Push-Belt and Sensor Wear from 120,000 km
The optional Autotronic CVT gearbox is considered the weak point of the W245. Typical faults: speed sensors, control unit, and premature push-belt wear. Repair costs frequently exceed the vehicle's value.
Symptoms: Judder when pulling away, unusual noises from gearbox, vehicle no longer shifts, gearbox stuck in one gear
+ 2 more engine weaknesses + vehicle weaknesses
Development of the M166 with CVT option. Turbo variant (200 Turbo) powerful but rare. Solid everyday engines with few typical failures.
- !! CVT Gearbox Loses Drive from 130,000 km
The Autotronic CVT (722.8) on the M266 is failure-prone: the push belt wears or the output speed sensor in the control unit fails. When faulty, only engine rpm rises on acceleration with no drive.
Symptoms: Engine revs climb, vehicle does not accelerate, CVT warning on display, no drive in D or R - !! Defective Gearbox Control Unit — Fault Codes P0706 / 0722 from 120,000 km
The CVT gearbox control unit develops faults in the internal speed sensor. Typical fault codes are P0706 and 0722/0723. New control unit requires manufacturer programming and is expensive.
Symptoms: Fault message 'Transmission — visit workshop', jerky shifting, vehicle stranding, gearbox limp mode - !! CVT Autotronic — Push-Belt and Sensor Wear from 120,000 km
The optional Autotronic CVT gearbox is considered the weak point of the W245. Typical faults: speed sensors, control unit, and premature push-belt wear. Repair costs frequently exceed the vehicle's value.
Symptoms: Judder when pulling away, unusual noises from gearbox, vehicle no longer shifts, gearbox stuck in one gear
+ 2 more engine weaknesses + vehicle weaknesses
Development of the M166 with CVT option. Turbo variant (200 Turbo) powerful but rare. Solid everyday engines with few typical failures.
- !! CVT Gearbox Loses Drive from 130,000 km
The Autotronic CVT (722.8) on the M266 is failure-prone: the push belt wears or the output speed sensor in the control unit fails. When faulty, only engine rpm rises on acceleration with no drive.
Symptoms: Engine revs climb, vehicle does not accelerate, CVT warning on display, no drive in D or R - !! Defective Gearbox Control Unit — Fault Codes P0706 / 0722 from 120,000 km
The CVT gearbox control unit develops faults in the internal speed sensor. Typical fault codes are P0706 and 0722/0723. New control unit requires manufacturer programming and is expensive.
Symptoms: Fault message 'Transmission — visit workshop', jerky shifting, vehicle stranding, gearbox limp mode - !! CVT Autotronic — Push-Belt and Sensor Wear from 120,000 km
The optional Autotronic CVT gearbox is considered the weak point of the W245. Typical faults: speed sensors, control unit, and premature push-belt wear. Repair costs frequently exceed the vehicle's value.
Symptoms: Judder when pulling away, unusual noises from gearbox, vehicle no longer shifts, gearbox stuck in one gear
+ 2 more engine weaknesses + vehicle weaknesses
Development of the M166 with CVT option. Turbo variant (200 Turbo) powerful but rare. Solid everyday engines with few typical failures.
- !! CVT Gearbox Loses Drive from 130,000 km
The Autotronic CVT (722.8) on the M266 is failure-prone: the push belt wears or the output speed sensor in the control unit fails. When faulty, only engine rpm rises on acceleration with no drive.
Symptoms: Engine revs climb, vehicle does not accelerate, CVT warning on display, no drive in D or R - !! Defective Gearbox Control Unit — Fault Codes P0706 / 0722 from 120,000 km
The CVT gearbox control unit develops faults in the internal speed sensor. Typical fault codes are P0706 and 0722/0723. New control unit requires manufacturer programming and is expensive.
Symptoms: Fault message 'Transmission — visit workshop', jerky shifting, vehicle stranding, gearbox limp mode - !! CVT Autotronic — Push-Belt and Sensor Wear from 120,000 km
The optional Autotronic CVT gearbox is considered the weak point of the W245. Typical faults: speed sensors, control unit, and premature push-belt wear. Repair costs frequently exceed the vehicle's value.
Symptoms: Judder when pulling away, unusual noises from gearbox, vehicle no longer shifts, gearbox stuck in one gear
+ 2 more engine weaknesses + vehicle weaknesses
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Autotronic CVT Gearbox: Failure and Costly Repair The continuously variable Autotronic gearbox fails frequently, often under 100,000 km. Faults in the control unit, drive belt or chain link belt lead to total loss. Repair rarely economical. Symptoms: Judder when pulling away, no forward drive, gearbox fault light, limp mode from 90,000 km | High |
Test Reports
TÜV Report 2024
The second A-Class generation achieves average MOT results with individual weak points at the brakes and electrics.
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Explore more
Known Problems and Issues +
A total of 19 weaknesses have been documented for the Mercedes-Benz A-Klasse W169 (2004–2012) — 11 engine-related and 8 vehicle-related. One problem engine: M266 (1.5-2.0L). Typical issues affect Gearbox, HVAC, Rust, Suspension.
A-Klasse (OM640, 2004–2012) — Be Careful: Injectors Leaking — Tar Deposits and Pressure Loss, Timing Chain Rattles — Chain Tensioner Worn, EGR Valve Coked Up and Stuck. Power: 82 PS.
A-Klasse (OM640, 2004–2012) — Be Careful: Injectors Leaking — Tar Deposits and Pressure Loss, Timing Chain Rattles — Chain Tensioner Worn, EGR Valve Coked Up and Stuck. Power: 109 PS.
A-Klasse (OM640, 2007–2012) — Be Careful: Injectors Leaking — Tar Deposits and Pressure Loss, Timing Chain Rattles — Chain Tensioner Worn, EGR Valve Coked Up and Stuck. Power: 136–140 PS.
A-Klasse (M266, 2004–2012) — Stay Away!: CVT Gearbox Loses Drive, Defective Gearbox Control Unit — Fault Codes P0706 / 0722, CVT Autotronic — Push-Belt and Sensor Wear. Power: 95 PS.
A-Klasse (M266, 2004–2012) — Stay Away!: CVT Gearbox Loses Drive, Defective Gearbox Control Unit — Fault Codes P0706 / 0722, CVT Autotronic — Push-Belt and Sensor Wear. Power: 116 PS.
A-Klasse (M266, 2004–2012) — Stay Away!: CVT Gearbox Loses Drive, Defective Gearbox Control Unit — Fault Codes P0706 / 0722, CVT Autotronic — Push-Belt and Sensor Wear. Power: 136–140 PS.
A-Klasse (M266, 2005–2012) — Stay Away!: CVT Gearbox Loses Drive, Defective Gearbox Control Unit — Fault Codes P0706 / 0722, CVT Autotronic — Push-Belt and Sensor Wear. Power: 193 PS.
What to watch out for with the Mercedes-Benz A-Klasse? See the detailed listing of all engine and vehicle weaknesses in the sections above.
Frequently Asked Questions
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Last updated: February 2026 · All information without guarantee