Mercedes-Benz A-Klasse W177
Weaknesses, engine ratings and buying advice
The A-Class W177 (2018–present) was the first car in the world with MBUX — and it shows: first-generation software, bug-prone, but a genuine technological leap. The elephant in the room is the base engine: the M282 is a Renault engine (H5Ht architecture, jointly developed with the Renault-Nissan-Mitsubishi Alliance). It's built in Kolleda, Thuringia — not at Renault's Valladolid plant — which matters. The architecture is nonetheless identical: same tooling for timing chain work, same fundamental structure as in the Clio and Captur.
Engine hierarchy: The M260 (2.0T, A 220/A 250, 163–224 hp) is Mercedes-own, unrelated to the M282, and regarded as reliable. The OM608/OM654 diesel (A 200d, 150 hp) is the most solid choice for long-distance driving — scored top marks in Auto Bild durability testing, real-world consumption 5.6 L/100 km. The M282 (1.3T, A 160/A 180/A 200) has thermal management issues: early thermostat failure, tendency to overheat if coolant level is low, elevated oil consumption with the wrong oil spec. Full timing chain repair (chain, guides, tensioner): $6,500. If buying M282: 2021 or newer, ask about coolant history, change oil every 10,000 km (not Mercedes Longlife at 25,000 km).
The DCT gearbox: The 7G/8G-DCT judders between 1,500–2,000 RPM and suffers clutch wear in city traffic. A recall was issued for gearbox oil underfill (2018–2020 production). Clutch pack: $1,700–3,500 from 80,000–120,000 km. Gearbox oil change every 40,000 km is essential — Mercedes calls it "lifetime fill," real-world experience says otherwise.
MBUX: Was the wow-factor in 2018 (Hey Mercedes voice control, adaptive learning system) — but first-generation means: right screen black after cold start, system freezes, voice control unresponsive. Many vehicles required repeated dealer software flashes. Stabilised from 2020/2021; the 2022 facelift brought MBUX Generation 2. Also: brake hoses flagged repeatedly at MOT, several recalls for camera systems (lane-keeping, eCall, LED multibeam).
AMG variants: A 35 AMG (225 kW, M260-based): uncomplicated, DCT tuned sportier. A 45/A 45 S (285/310 kW, M139): world's most powerful production four-cylinder per litre, surprisingly robust but operating at extreme temperatures. Used from $42,000–60,000.
Test-drive checklist: DCT judder below 20 km/h, MBUX boot time after cold start (>10 sec = problem), A/C condensate smell (drain hose recall), rear rattling over bumps (dampers/multi-link). At MOT, 92–94% pass without defects — significantly better than class average.
2026 market: A 160/A 180 (M282) $16,000–22,000. A 200d $20,000–28,000. A 250 (M260) $24,000–33,000. A 35 AMG $32,000–44,000. Insider pick: A 250 with M260 or A 200d with OM608 — anyone wanting a "pure Mercedes engine" avoids the M282. If buying A 180 regardless: 2021+, check coolant history, oil every 10,000 km, never drive with low coolant.
421 PS
AMG A 45 S · Benzin
421 hp Four-Cylinder — World Record
Legendary!109–163 PS
1.3L Turbo Benzin
5 weaknesses
Good ChoiceGenerations
Engine Overview
The Mercedes-Benz A-Klasse W177 is available with 12 engine variants — from 90 to 421 hp.
Renault-based small diesel, new generation. Economical with SCR catalyst, but still with little power reserve. Automatic only.
- !! Timing belt maintenance obligation from 120,000 km
Like its Renault counterpart, the OM608 uses a timing belt. Prescribed change every 120,000 km or 6 years -- frequently forgotten as Mercedes buyers are accustomed to timing chains.
Symptoms: No warning on snap -- sudden engine failure and severe engine damage - !! Timing belt change critical from 120,000 km
The OM608 (Renault K9K base) uses a timing belt. Mercedes specifies 200,000 km change interval; Renault prescribes 120,000 km for the same engine. A snap causes immediate total damage on this interference engine.
Symptoms: No noticeable warning before snap; beforehand: faint squealing, occasionally starting difficulties - !! Increased oil consumption / turbo shaft seal from 100,000 km
The Renault-based OM608 1.5 CDI sometimes shows increased oil consumption from early on due to a leaking turbocharger shaft seal. Oil mist in the intake tract behind the turbo.
Symptoms: Dropping oil level, oil mist or blue smoke from exhaust, oil in air filter housing behind turbo
+ 2 more engine weaknesses + vehicle weaknesses
Completely new aluminium diesel with NANOSLIDE coating and integrated particulate filter. Noticeably quieter and cleaner than the OM651. Few typical faults known to date.
- !! Rocker Arm and Camshaft Wear from 80,000 km
Known weak point: the narrow camshaft lobes and rocker arms in the OM654 wear prematurely due to inadequate lubrication. Mercedes issued TSBs.
Symptoms: Ticking or knocking from engine bay, misfires, rough running, engine warning light - !! Electric Coolant Pump Leaking — Recall
Over 800,000 Mercedes diesel vehicles with OM654/OM656 were recalled due to a leaking electric coolant pump. Coolant loss can lead to overheating.
Symptoms: Coolant loss, overheating warning, coolant warning light, engine temperature rises - !! NOx Sensor Defective — AdBlue Fault and Start Inhibit from 90,000 km
NOx sensors wear out from soot particles and deliver erroneous readings. Consequence: incorrect AdBlue injection, CEL illumination; if unaddressed, an engine start inhibit may follow. Both sensors can be affected.
Symptoms: CEL, AdBlue warning, fault code P20EE or P204F, message 'No start after X km', rough idle
+ 8 more engine weaknesses + vehicle weaknesses
Completely new aluminium diesel with NANOSLIDE coating and integrated particulate filter. Noticeably quieter and cleaner than the OM651. Few typical faults known to date.
- !! Rocker Arm and Camshaft Wear from 80,000 km
Known weak point: the narrow camshaft lobes and rocker arms in the OM654 wear prematurely due to inadequate lubrication. Mercedes issued TSBs.
Symptoms: Ticking or knocking from engine bay, misfires, rough running, engine warning light - !! Electric Coolant Pump Leaking — Recall
Over 800,000 Mercedes diesel vehicles with OM654/OM656 were recalled due to a leaking electric coolant pump. Coolant loss can lead to overheating.
Symptoms: Coolant loss, overheating warning, coolant warning light, engine temperature rises - !! NOx Sensor Defective — AdBlue Fault and Start Inhibit from 90,000 km
NOx sensors wear out from soot particles and deliver erroneous readings. Consequence: incorrect AdBlue injection, CEL illumination; if unaddressed, an engine start inhibit may follow. Both sensors can be affected.
Symptoms: CEL, AdBlue warning, fault code P20EE or P204F, message 'No start after X km', rough idle
+ 8 more engine weaknesses + vehicle weaknesses
Joint development with Renault (H5Ht). Cylinder bore coating: NANOSLIDE. Compact and economical, but somewhat strained under high load. Also used as PHEV base (250e).
- !! Increased oil consumption from 60,000 km
Some M282 engines show early increased oil consumption from defective piston rings and oil scraper rings. The problem sometimes appears at low mileages.
Symptoms: Dropping oil level between service visits, occasionally slight blue smoke when accelerating - !! Increased oil consumption from piston ring wear from 60,000 km
Some M282 engines show progressive oil consumption from low mileage. Cause: defective oil rings or pistons. Direct injection washes oil off the cylinder wall.
Symptoms: Regular oil top-ups required, no visible leaks, no smoke from exhaust - !! Boost pressure loss from turbo or charge air hose from 120,000 km
The M282 turbocharger can lose power at higher mileage from bearing wear or leaking charge air pipes. The wastegate actuator can deliver incorrect signals.
Symptoms: Power drop at full throttle, whistling in the engine bay, boost pressure too low warning (P0299)
+ 2 more engine weaknesses + vehicle weaknesses
Joint development with Renault (H5Ht). Cylinder bore coating: NANOSLIDE. Compact and economical, but somewhat strained under high load. Also used as PHEV base (250e).
- !! Increased oil consumption from 60,000 km
Some M282 engines show early increased oil consumption from defective piston rings and oil scraper rings. The problem sometimes appears at low mileages.
Symptoms: Dropping oil level between service visits, occasionally slight blue smoke when accelerating - !! Increased oil consumption from piston ring wear from 60,000 km
Some M282 engines show progressive oil consumption from low mileage. Cause: defective oil rings or pistons. Direct injection washes oil off the cylinder wall.
Symptoms: Regular oil top-ups required, no visible leaks, no smoke from exhaust - !! Boost pressure loss from turbo or charge air hose from 120,000 km
The M282 turbocharger can lose power at higher mileage from bearing wear or leaking charge air pipes. The wastegate actuator can deliver incorrect signals.
Symptoms: Power drop at full throttle, whistling in the engine bay, boost pressure too low warning (P0299)
+ 2 more engine weaknesses + vehicle weaknesses
Joint development with Renault (H5Ht). Cylinder bore coating: NANOSLIDE. Compact and economical, but somewhat strained under high load. Also used as PHEV base (250e).
- !! Increased oil consumption from 60,000 km
Some M282 engines show early increased oil consumption from defective piston rings and oil scraper rings. The problem sometimes appears at low mileages.
Symptoms: Dropping oil level between service visits, occasionally slight blue smoke when accelerating - !! Increased oil consumption from piston ring wear from 60,000 km
Some M282 engines show progressive oil consumption from low mileage. Cause: defective oil rings or pistons. Direct injection washes oil off the cylinder wall.
Symptoms: Regular oil top-ups required, no visible leaks, no smoke from exhaust - !! Boost pressure loss from turbo or charge air hose from 120,000 km
The M282 turbocharger can lose power at higher mileage from bearing wear or leaking charge air pipes. The wastegate actuator can deliver incorrect signals.
Symptoms: Power drop at full throttle, whistling in the engine bay, boost pressure too low warning (P0299)
+ 2 more engine weaknesses + vehicle weaknesses
Powerful two-litre turbo from the new compact platform. 7G-DCT or 8G-DCT standard. Strong everyday engine with few known weaknesses.
- !! Exhaust Valve Seat Insert Wear / Cylinder Head from 40,000 km
Known production deficiency: exhaust valve seat inserts and valve guides wear prematurely, leading to leaking combustion chambers. Mercedes extended warranty to 15 years / 241,000 km for model years 2019–2022.
Symptoms: Rough engine running, misfires (faults P0300–P0304), check engine light, power loss, vibration - !! Timing Chain Rattles on Cold Start from 90,000 km
On the M260 timing chain and tensioner can wear prematurely, especially with long oil change intervals. Affected vehicles show rattling on cold start.
Symptoms: Metallic rattling after cold start, check engine light, camshaft position fault codes - !! Wastegate Actuator Causes Boost Pressure Loss from 100,000 km
The wastegate actuator on the M260 can open prematurely from spring wear, leading to underboost. Diagnosis possible by pressure-testing the actuator.
Symptoms: Power deficiency under load, P0299 fault code, whistling on acceleration
+ 2 more engine weaknesses + vehicle weaknesses
Powerful two-litre turbo from the new compact platform. 7G-DCT or 8G-DCT standard. Strong everyday engine with few known weaknesses.
- !! Exhaust Valve Seat Insert Wear / Cylinder Head from 40,000 km
Known production deficiency: exhaust valve seat inserts and valve guides wear prematurely, leading to leaking combustion chambers. Mercedes extended warranty to 15 years / 241,000 km for model years 2019–2022.
Symptoms: Rough engine running, misfires (faults P0300–P0304), check engine light, power loss, vibration - !! Timing Chain Rattles on Cold Start from 90,000 km
On the M260 timing chain and tensioner can wear prematurely, especially with long oil change intervals. Affected vehicles show rattling on cold start.
Symptoms: Metallic rattling after cold start, check engine light, camshaft position fault codes - !! Wastegate Actuator Causes Boost Pressure Loss from 100,000 km
The wastegate actuator on the M260 can open prematurely from spring wear, leading to underboost. Diagnosis possible by pressure-testing the actuator.
Symptoms: Power deficiency under load, P0299 fault code, whistling on acceleration
+ 2 more engine weaknesses + vehicle weaknesses
Joint development with Renault (H5Ht). Cylinder bore coating: NANOSLIDE. Compact and economical, but somewhat strained under high load. Also used as PHEV base (250e).
- !! Increased oil consumption from 60,000 km
Some M282 engines show early increased oil consumption from defective piston rings and oil scraper rings. The problem sometimes appears at low mileages.
Symptoms: Dropping oil level between service visits, occasionally slight blue smoke when accelerating - !! Increased oil consumption from piston ring wear from 60,000 km
Some M282 engines show progressive oil consumption from low mileage. Cause: defective oil rings or pistons. Direct injection washes oil off the cylinder wall.
Symptoms: Regular oil top-ups required, no visible leaks, no smoke from exhaust - !! Boost pressure loss from turbo or charge air hose from 120,000 km
The M282 turbocharger can lose power at higher mileage from bearing wear or leaking charge air pipes. The wastegate actuator can deliver incorrect signals.
Symptoms: Power drop at full throttle, whistling in the engine bay, boost pressure too low warning (P0299)
+ 2 more engine weaknesses + vehicle weaknesses
AMG version of the M260 with 306 hp. 7G-DCT and 4MATIC standard. Independent tuning with reinforced bottom end. Good balance of everyday usability and performance.
- !! Cylinder Head Exhaust Valves Worn from 35,000 km
Same production defect as in the standard M260: exhaust valve seat inserts wear prematurely causing engine misfires. Mercedes extended warranty to 15 years.
Symptoms: Heavy vibration, misfires (MIL with misfire faults P030x), noticeable power loss - !! Valve Seat Insert Wears — Cylinder Head Damage from 50,000 km
Known production issue on early M260 engines: exhaust valve seat inserts wear prematurely. Mercedes Canada extended warranty to 15 years/241,000 km.
Symptoms: Misfires, rough running, power loss, compression test shows drop, MIL illuminated - !! Turbocharger Wear Under AMG Load from 90,000 km
The higher-boosted M260 shows premature turbocharger wear with spirited driving. Inadequate cool-down periods accelerate bearing damage.
Symptoms: Whistling from turbo, power drop at high rpm, oil mist in intake tract
+ 2 more engine weaknesses + vehicle weaknesses
The M139 is the logical development of the M133 and surpasses it in every respect: more power, better thermal management through an improved cooling concept, combined direct and port injection to fight intake valve carbon build-up. As a young engine with limited long-term data it is considered robust so far. Isolated reports of coolant sensor issues and water pump failures at high speeds. Tuning potential is enormous, but fuel supply must be upgraded at higher power levels.
- !! Turbocharger Stress Under Extreme Use from 100,000 km
The world's most powerful series-production four-cylinder at 421 hp subjects its turbocharger to extreme stress. Without adequate cool-down periods after full-load operation, premature bearing wear is likely.
Symptoms: Whistling at high load, oil mist in intake tract, power drop in heat - !! Turbocharger Shaft Seal Leaking from 80,000 km
The high-performance turbocharger on the M139 can push oil into the intake tract due to excessive shaft play. Early vehicles were subject to a recall for turbocharger bearing defects.
Symptoms: Oil consumption without visible leaks, smoke cloud on cold start, power drop under high load - !! Overheating After Spirited Driving from 60,000 km
The M139 cooling system is designed at its limits. After extended high-load phases coolant temperature can reach critical values, especially in warm weather.
Symptoms: Coolant temperature warning after spirited driving, restricted engine power through thermal management
+ 3 more engine weaknesses + vehicle weaknesses
The M139 is the logical development of the M133 and surpasses it in every respect: more power, better thermal management through an improved cooling concept, combined direct and port injection to fight intake valve carbon build-up. As a young engine with limited long-term data it is considered robust so far. Isolated reports of coolant sensor issues and water pump failures at high speeds. Tuning potential is enormous, but fuel supply must be upgraded at higher power levels.
- !! Turbocharger Stress Under Extreme Use from 100,000 km
The world's most powerful series-production four-cylinder at 421 hp subjects its turbocharger to extreme stress. Without adequate cool-down periods after full-load operation, premature bearing wear is likely.
Symptoms: Whistling at high load, oil mist in intake tract, power drop in heat - !! Turbocharger Shaft Seal Leaking from 80,000 km
The high-performance turbocharger on the M139 can push oil into the intake tract due to excessive shaft play. Early vehicles were subject to a recall for turbocharger bearing defects.
Symptoms: Oil consumption without visible leaks, smoke cloud on cold start, power drop under high load - !! Overheating After Spirited Driving from 60,000 km
The M139 cooling system is designed at its limits. After extended high-load phases coolant temperature can reach critical values, especially in warm weather.
Symptoms: Coolant temperature warning after spirited driving, restricted engine power through thermal management
+ 3 more engine weaknesses + vehicle weaknesses
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| 7G/8G-DCT Judders When Pulling Away and at Low RPM The dual clutch gearbox in the W177 exhibits juddering and rough pull-away between 1,500–2,000 RPM. At high mileages and in urban use the clutch packs wear prematurely. Software updates alleviate the problem but do not resolve it permanently. Symptoms: Juddering when pulling away, abrupt gear changes, 1st gear occasionally drops out, engine revs high on kickdown from 80,000 km | High |
Test Reports
TÜV Report 2024
The current A-Class generation shows very low fault rates at the first MOT inspections and ranks among the best compact cars.
2023-11ADAC Breakdown Statistics 2024
The current A-Class achieves very good results in breakdown frequency and ranks among the most reliable compact cars of its registration years.
2024-04Top Reported Issues
Alternatives
Acura Integra DE5
Compact (2023–2025)
Citroën C4 X I
Compact (2023–2026)
VW ID.3 I-FL
Compact (2023–2026)
BMW 2er U06
Compact (2022–2025)
Honda Civic Type R FL5
Compact (2022–2026)
Hyundai Elantra N CN7 N
Compact (2022–2025)
Explore more
Known Problems and Issues +
A total of 48 weaknesses have been documented for the Mercedes-Benz A-Klasse W177 (2018–2025) — 37 engine-related and 11 vehicle-related. Typical issues affect Gearbox, Other, Electronics, Cooling. Considered reliable: M282 (1.3L Turbo), M139 (2.0L Turbo AMG).
A-Klasse (OM608, 2018–2025) — Be Careful: Timing belt maintenance obligation, Timing belt change critical, Increased oil consumption / turbo shaft seal. Power: 109–116 PS.
A-Klasse (OM654, 2018–2025) — Be Careful: Rocker Arm and Camshaft Wear, Electric Coolant Pump Leaking — Recall, NOx Sensor Defective — AdBlue Fault and Start Inhibit. Power: 150 PS.
A-Klasse (OM654, 2018–2025) — Be Careful: Rocker Arm and Camshaft Wear, Electric Coolant Pump Leaking — Recall, NOx Sensor Defective — AdBlue Fault and Start Inhibit. Power: 190 PS.
A-Klasse (M260, 2018–2025) — Be Careful: Exhaust Valve Seat Insert Wear / Cylinder Head, Timing Chain Rattles on Cold Start, Wastegate Actuator Causes Boost Pressure Loss. Power: 184–190 PS.
A-Klasse (M260, 2018–2025) — Be Careful: Exhaust Valve Seat Insert Wear / Cylinder Head, Timing Chain Rattles on Cold Start, Wastegate Actuator Causes Boost Pressure Loss. Power: 218–224 PS.
A-Klasse (M260-AMG35, 2018–2025) — Be Careful: Cylinder Head Exhaust Valves Worn, Valve Seat Insert Wears — Cylinder Head Damage, Turbocharger Wear Under AMG Load. Power: 306 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
What problems and weaknesses does the Mercedes-Benz A-Klasse W177 have? +
What should I look for when buying a used Mercedes-Benz A-Klasse W177? +
Which engine is recommended? +
Which Mercedes-Benz A-Klasse W177 engine is the most reliable? +
Which Mercedes-Benz A-Klasse W177 engine is the most fun? +
Is the Mercedes-Benz A-Klasse W177 worth buying used? +
What horsepower variants are available for the Mercedes-Benz A-Klasse W177? +
Last updated: February 2026 · All information without guarantee