Log inCheck a car
Known Faults Database

Mercedes-Benz B-Class problems, reliability and years to avoid

If you are considering buying a used Mercedes-Benz B-Class, these are the common problems worth knowing about first. Our garage database tracks 4 known faults for this model, 3 of them rated high severity. Every one below is a repair bill a seller has good reason not to mention.

Free advert check

Found a Mercedes-Benz B-Class for sale?

Paste the advert and we read it against its known faults, its MOT history and the DVLA record, and tell you what the seller has not. Free, about a minute, no card.

Check a Mercedes-Benz B-Class advert (free) →
Works with any listing: paste the text from AutoTrader, Gumtree, eBay, Facebook Marketplace or a dealer’s own site.

Is the Mercedes-Benz B-Class reliable?

The Mercedes-Benz B-Class has 4 known faults in our database across 2 generations, 3 of them rated high severity. The most serious are engine (timing chain stretch and leaking hydraulic tensioners on the M270 turbo petrol) and gearbox (the 722.8 Autotronic CVT's internal gearbox ECU fails). None of them makes the car a bad buy on its own; the risk is a seller who knows and says nothing.

That is a count of the faults we hold, not a reliability score. Popular cars get written about more, and a newer generation has had less time to show its faults.

Which Mercedes-Benz B-Class years should you avoid?

No year is a write-off on its own. What matters is which serious faults a given year and engine can have, and whether the car in front of you has had them fixed.

W169 / W245, 2004 to 20121 high severity
1 known fault, the serious ones in the gearbox
W176 / W246 / C117 / X156, 2013 to 20182 high severity
3 known faults, the serious ones in the engine, electrics

Years and engines with a serious known fault

  • 2012 to 2018, 1.6 / 2.0 Turbo Petrol (M270), e.g. A180/A200/A250, B180/B200/B250, CLA 180/200/250, GLA 180/200/250: timing chain stretch and leaking hydraulic tensioners on the M270 turbo petrol
  • 2004 to 2012, All with CVT automatic (722.8 Autotronic): the 722.8 Autotronic CVT's internal gearbox ECU fails
  • 2011 to 2017, All variants: the steering column clock spring breaks

Each one is set out in full below, with the symptoms, the typical mileage and a rough repair cost.

Generation 1 of 21 known fault · 6 owner reports · 1 good note

Mercedes-Benz B-Class W169 / W245 (2004 to 2012) problems

Transmission/ClutchHigh severity🔧 Specialist mechanic

The 722.8 Autotronic CVT's internal gearbox ECU fails (speed sensor circuits break down inside the sealed unit), throwing 'Transmission Visit Workshop' on the dash and dropping the car into limp mode with limited or no gear selection. A main dealer fix means a new ECU, valve body and coding at well over 1000 pounds; even specialist ECU rebuilds with fitting typically run 500-1000 pounds. Mileage is no guide to safety here: owner reports have it failing at 27,500, 30,000, 37,538, 43,000, 56,000 and 62,000 miles, and the valve body behind it was reported failing at around 70,000 miles

Rough guide
£600-2000

Typical symptoms

  • 'Transmission Visit Workshop' warning on the dash
  • sudden limp mode or loss of drive
  • harsh or absent gear engagement, stuck in one ratio

Affected vehicles

Engines:
All with CVT automatic (722.8 Autotronic)
Typical mileage:
27000-70000 miles
4 more owner reports back this up
  • March 2018The Autotronic CVT gearbox in a 2010 B-Class failed at 62,000 miles, with a replacement quoted at £4,200 by the dealer.
  • September 2017A 2011 B-Class CVT transmission experienced trouble at 30,000 miles, going into "racing mode" due to a secondary speed sensor defect; repair cost £1,439.68.
  • August 2011Autotronic CVT valve bodies began failing after six years and around 70,000 miles, with replacement costing £1,250.
  • April 2010The Autotronic CVT automatic gearbox in a 2006 B200CDI SE failed at 43,000 miles, with a quoted repair cost of £5,355 after a contribution.
🔍 We have a specific pre-purchase check for this faultCheck an advert →

What owners report on the W169 / W245

6 single reports, unconfirmed

One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.

  • Engine · December 2019The engine air intake of a 2009 B160 Blue Efficiency petrol model "blew up" in France, requiring eight weeks for repatriation.
  • Bodywork · March 2018Water entered the load area and spare wheel well of a B-Class through broken one-way cabin vents, costing £1,200 to repair.
  • Electrics · December 2016The EIS ignition switch module in a 2011 B200 failed twice, preventing the car from starting; the first replacement cost £500.
  • Bodywork · March 2015Seals around cabin vent flaps in a 2005-2012 B-Class failed, causing the spare wheel well to fill with water.
  • Bodywork · March 2014Blocked bulkhead vent wells on a 2005-2012 B-Class led to the battery compartment flooding and the pollen filter becoming sodden.
  • Interior · August 2012The air conditioning condensers on a B-Class were found to be vulnerable to stone damage.

What owners like about the W169 / W245

1 note
  • The B-Class achieved the top position for customer satisfaction in the MPV sector in the 2010 JD Power Survey.
Generation 2 of 23 known faults · 5 owner reports · 4 good notes

Mercedes-Benz B-Class W176 / W246 / C117 / X156 (2013 to 2018) problems

Engine/EmissionsHigh severity📝 Editorial

Timing chain stretch and leaking hydraulic tensioners on the M270 turbo petrol. The chain rattles on cold start as the tensioner loses oil pressure; left alone the plastic guides wear, the chain can skip a tooth and throw camshaft timing codes (P0016/P0017 family), and in the worst case the valves contact the pistons. The transverse installation in these front drive cars makes the repair far more labour intensive than on rear drive Mercedes

Rough guide
£Unknown

Typical symptoms

  • metallic rattle from the engine for several seconds on cold start-up
  • engine management light with camshaft timing fault codes
  • rough running or misfire once the chain has jumped

Affected vehicles

Engines:
1.6 / 2.0 Turbo Petrol (M270), e.g. A180/A200/A250, B180/B200/B250, CLA 180/200/250, GLA 180/200/250
Typical mileage:
Unknown miles
🔍 We have a specific pre-purchase check for this faultCheck an advert →
Transmission/ClutchMedium severity🔧 Specialist mechanic

The 7G-DCT dual-clutch automatic suffers low-speed judder and jerky shifts as the wet clutch packs wear, and mechatronic (electrohydraulic control unit) failures that cause delayed engagement, harsh 2nd-3rd shifts, limp mode or loss of drive. Mechatronic replacement is quoted at 1200-1800 pounds by UK specialists; clutch pack replacement is similar. Neglected 40k-mile fluid changes accelerate both

Rough guide
£1200-2500

Typical symptoms

  • shuddering or juddering when pulling away from a stop
  • hesitation or a lurch when setting off, worse when cold
  • clunk into P, N or R, or harsh low-gear shifts
  • gearbox warning and limp mode in advanced cases

Affected vehicles

Engines:
All with 7G-DCT dual-clutch automatic (Getrag 724.0)
Typical mileage:
50000-100000 miles
7 more owner reports back this up
  • July 2019A 2014 B180 petrol 7G-DCT experienced reverse gear problems four times, with a dashboard warning appearing shortly after starting a journey.
  • May 2018An 18,000-mile 2014 B180d with 7G-DCT automatic transmission sometimes moved sluggishly from standstill and had inconsistent gear changes.
  • August 2017The clutch of a 7G-DCT transmission in a February 2016 B-Class Diesel Sport failed at 18,000 miles, requiring a new CVT transmission.
  • August 2017A 2016 B200d with 7G-DCT transmission experienced a failure to engage drive.
  • August 2017A 2014 B220 Sport 4-Matic with 7G-DCT dual clutch transmission had random speed surges at low speeds and intermittent starting failures.
  • July 2017A 2016 B200 petrol 7G-DCT experienced "surging" on upchanges from first to second gear at low speeds and when driving downhill.
  • July 2016A 2016 B200 petrol DCT auto had sudden surges at low speeds around 15mph, particularly during the first to second gear change.
🔍 We have a specific pre-purchase check for this faultCheck an advert →
ElectricalHigh severity🏛️ Official recall

The steering column clock spring breaks and, with the steering airbag wiring insufficiently earthed, can short-circuit and set off the steering wheel airbag unexpectedly. DVSA covers it with seven recall campaigns launched between December 2017 and July 2018 (R/2017/282, R/2018/006, R/2018/055, R/2018/069, R/2018/098, R/2018/130 and R/2018/154), spanning the A-Class, B-Class, C-Class, CLA, E-Class, GLA and GLC built from June 2011 to July 2017. The largest single campaign covers 84,879 cars and the seven campaign totals add up to over 400,000. The work is free and has no time limit, but cars still change hands with it outstanding.

Rough guide
£0 (free safety recall)

Typical symptoms

  • Airbag warning light appearing on the dashboard
  • Unexpected airbag deployment

Affected vehicles

Engines:
All variants
Typical mileage:
All mileages miles
🔍 We have a specific pre-purchase check for this faultCheck an advert →

What owners report on the W176 / W246 / C117 / X156

5 single reports, unconfirmed

One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.

  • Engine · March 2020A 2013 B180 CDI experienced engine failure with a noisy main bearing at under 23,000 miles, requiring a new engine at an £8,000 cost.
  • Electrics · August 2019A 2015 B250e Electric at 68,000 miles displayed a "visit workshop" message; a new battery was recommended for £5,000, with the manufacturer covering half.
  • Electrics · March 2019The 12-volt battery in a B-Class 250 E Sport EV went flat overnight while charging, due to a continuously clicking charging relay.
  • Gearbox and clutch · November 2018A fairly new Mercedes B-Class with the 7G-DCT automatic transmission developed a crunching noise during operation.
  • Electrics · June 2015The Pre-Safe system of a September 2012 B180CDI failed, causing random power loss and parking brake failure, even after software updates.

What owners like about the W176 / W246 / C117 / X156

4 notes
  • The B-Class provides ample cabin room for all occupants, complemented by a spacious boot expandable via a sliding rear seat.
  • Every B-Class model comes equipped with extensive safety features, including emergency braking as a standard inclusion.
  • All B-Class engines are economical, with even the most powerful versions producing low CO2 emissions.
  • The B220 CDI impressed with its power and the smooth shifting of the new seven-speed dual-clutch transmission.
Other years0 known faults · 1 owner report · 2 good notes

Other Mercedes-Benz B-Class years: owner reports

What owners report

1 single report, unconfirmed

One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.

  • Gearbox and clutch · October 2019A May 2019 B180 AMG Line Premium Auto had occasional front clunking, engine surges when moving off cold, and intermittent reverse gear selection issues.

What owners like

2 notes
  • The latest Mercedes-Benz B-Class model features a significantly improved aesthetic design compared to its two predecessors.
  • The B-Class achieved a five-star Euro NCAP safety rating, with high scores for adult, child, pedestrian protection, and safety assist.

Sellers rarely admit these faults outright

We track 11 specific phrases sellers use in adverts to soft-pedal these exact issues. Paste any Mercedes-Benz B-Class advert and we check it in seconds.

Check an advert now (free) →
Free report, no credit card required.

Mercedes-Benz B-Class recalls

Recall work is done by the manufacturer, and GOV.UK says you will not usually have to pay for it. These are the 45 DVSA recalls for the B-Class, newest first. They do not tell you whether this particular car has had the work: for that, put the registration into the free GOV.UK MOT history check, which shows a recall status where the manufacturer shares it, or ask a franchised dealer to check the VIN.

🏛️ May 2024Cars built July 2018 to January 2024

SRPC2404 - Backup function of steering software

On affected vehicles the backup function of the steering software might not meet specifications. As a result the steering power support might be impaired and a loss of steerability cannot be ruled out.

Put right by: Update the software of the electric steering on the affected vehicles.

DVSA R/2024/16610,592 vehicles affected in the UK
🏛️ March 2023Cars built May 2015 to April 2017

Affected vehicles have an engine control unit software that deviates from the local legal requirements

Affected vehicles have an engine control unit software that deviates from the local legal requirements.

Put right by: Update the diesel engine control unit software.

DVSA R/2023/0622,593 vehicles affected in the UK
🏛️ December 2021Cars built May 2010 to May 2012

Update to improve emissions

As a result of a directive from Germanys Federal Motor Transport Authority (KBA) changes are required to certain specific calibration functions within the engine management systems of certain vehicles.

Put right by: Conduct an update to the diesel engine control unit software.

DVSA R/2021/3996,014 vehicles affected in the UK
🏛️ December 2021Cars built June 2012 to July 2013

Update to the diesel engine control unit software to improve the emissions

As a result of a directive from Germanys Federal Motor Transport Authority (KBA) changes are required to certain specific calibration functions within the engine management systems of certain vehicles.

Put right by: Conduct an update to the diesel engine control unit software.

DVSA R/2021/40231,414 vehicles affected in the UK
🏛️ November 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/376100,780 vehicles affected in the UK
🏛️ July 2021Cars built November 2016 to February 2017

A bore in the universal joint on the steering shaft might not meet specifications

A bore in the universal joint on the steering shaft might not meet specifications.

Put right by: Check the steering shaft on the affected vehicles and replace it if necessary.

DVSA R/2021/20227,414 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/110217,942 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/120173,208 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/111181,432 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/131162,534 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/13220,820 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/133213,330 vehicles affected in the UK
🏛️ May 2021Cars built January 2016 to January 2021

The behaviour of the emergency call system might not meet specifications

The behaviour of the emergency call system might not meet specifications.

Put right by: Update the software of the communication module for the emergency call system.

DVSA R/2021/134325,162 vehicles affected in the UK
🏛️ March 2021Cars built May 2016 to July 2020

The communication module may be deactivated

The communication module may be deactivated

Put right by: Carry out a check of the configuration of the communication module on affected vehicles and if necessary activate the communication module.

DVSA R/2021/08224 vehicles affected in the UK
🏛️ October 2020Cars built December 2019 to January 2020

An electrical contact inside the engine control unit may not meet the specification

An electrical contacting inside the engine control unit might not meet the specification

Put right by: Replace the engine control unit on the affected vehicles

DVSA R/2020/27737 vehicles affected in the UK
🏛️ October 2020Cars built October 2019 to June 2020

The oil supply line of the turbocharger may leak

The oil supply line of the turbocharger might leak

Put right by: Check the oil supply line of the turbocharger on the affected vehicles and replace it if necessary

DVSA R/2020/2621,074 vehicles affected in the UK
🏛️ October 2020Cars built March 2017 to September 2018

THE EMERGENCY CALL SYSTEM (eCall) DOES NOT MEET THE SPECIFICATION

On affected vehicles the software of the communication module for the emergency call system does not meet the specification

Put right by: Update the software of the communication module for the emergency call system

DVSA R/2020/2363,127 vehicles affected in the UK
🏛️ July 2020Cars built April 2015 to November 2017

The calibration of the occupant classification system for the passenger seat may not meet the specification

The calibration of the occupant classification system for the passenger seat might not meet the specification.

Put right by: Replace the passenger seat cushion

DVSA R/2019/44675 vehicles affected in the UK
🏛️ November 2019Cars built January 2012 to October 2013

The refrigerant in the air conditioning system does not meet legal requirements

The refrigerant used in the air conditioning system does not meet legal requirements.

Put right by: The air conditioning system will be adapted for the usage of the new refrigerant.

DVSA R/2019/327624 vehicles affected in the UK
🏛️ November 2019Cars built November 2012 to October 2013

The refrigerant used in the air condition system does not meet legal requirements

The refrigerant used in the air conditioning system does not meet legal requirements.

Put right by: Adapt the air conditioning system for usage of the new refrigerant.

DVSA R/2019/3541,407 vehicles affected in the UK
🏛️ November 2019Cars built November 2012 to October 2013

The refrigerant used in the air conditioning system may not meet legal requirements

The refrigerant used in the air conditioning system does not meet legal requirements

Put right by: The air conditioning system will be adapted for the usage of the new refrigerant.

DVSA R/2019/34858 vehicles affected in the UK
🏛️ September 2019Cars built February 2017 to July 2019

The software of the radar control unit may not meet specification

; The software of the radar control unit might not meet the specification

Put right by: Update the software of the radar sensor control unit on the affected vehicles.

DVSA R/2019/269294 vehicles affected in the UK
🏛️ September 2019Cars built November 2012 to October 2013

Air condition system refridgerant does not meet requirements

The refrigerant used in the air condition system does not meet legal requirements.

Put right by: The air conditioning system to be adapted for the usage of the new refrigerant (R1234yf).

DVSA R/2019/2217,516 vehicles affected in the UK
🏛️ July 2019Cars built July 2018 to February 2019

The software of the transmission control unit might not meet specification.

Under certain circumstances it might not be possible to shift into Drive or Reverse mode.

Put right by: Update the transmission control unit software of the affected vehicles.

DVSA R/2019/2171,209 vehicles affected in the UK
🏛️ April 2019Cars built July 2018 to February 2019

The driver might temporarily not be able to deactivate the high beam with the high beam lever.

The driver might temporarily not be able to deactivate the high beam with the high beam lever.

Put right by: The software is to be updated on affected vehicles.

DVSA R/2019/105957 vehicles affected in the UK
🏛️ April 2019Cars built August 2018 to December 2018

The locknuts securing the airbag might be insufficiently tightened

One or more of the four locknuts securing the drivers airbag might be insufficiently tightened.

Put right by: Replace the driver airbag of affected vehicles.

DVSA R/2019/0973 vehicles affected in the UK
🏛️ February 2019Cars built January 2018 to February 2018

The calibration of the front passenger seat occupant clasification system may not correspond to specifications

Incorrect calibration of the front passenger occupant classification system.

Put right by: Replace the seat cushion of the front passenger seat.

DVSA R/2018/349163 vehicles affected in the UK
🏛️ November 2018Cars built October 2017 to April 2018

Doors on left vehicle side (passenger side) remain permanently locked after the vehicle has been locked/unlocked with the remote control key

Possible inability to open the left hand door externally or internally.

Put right by: Replace the affected door locks on the left side of the vehicle.

DVSA R/2018/2685,030 vehicles affected in the UK
🏛️ June 2018Cars built November 2011 to July 2017

Electrical wiring in steering assembly may be insufficiently grounded

The steering column clock spring may break. This will cause warning messages to illuminate in the instrument cluster but in extreme instances it may cause the driver's airbag to deploy.

Put right by: Affected vehicles will be recalled to establish sufficient grounding of the steering components

DVSA R/2018/13078,608 vehicles affected in the UK
🏛️ May 2018Cars built November 2011 to July 2017

Steering components may be insufficiently grounded

It has been determined that the steering airbag electrical components are insufficiently grounded. Failure of the steering column module clock spring could result in an inadvertent deployment of the driver airbag which may cause risk of injury to the driver and an increased risk of a potential collision.

Put right by: On affected vehicles the manufacturer will fit a contact bridge to the outer race of the steering column top bearing which will provide correct grounding.

DVSA R/2018/09874,329 vehicles affected in the UK
🏛️ April 2018Cars built November 2011 to July 2017

Electrical wiring in steering assembly may be insufficiently grounded

The steering column clock spring may break. This will cause warning messages to illuminate in the instrument cluster but in extreme instances it may cause the driver's airbag to deploy.

Put right by: Affected vehicles will be recalled to establish sufficient grounding of the steering components.

DVSA R/2018/06967,027 vehicles affected in the UK
🏛️ December 2017Cars built November 2011 to July 2017

Electrical wiring in steering assembly may be insufficiently grounded

The steering column clock spring may break. This will cause warning messages to illuminate in the instrument cluster but in extreme instances it may cause the driver's airbag to deploy.

Put right by: Affected vehicles will be recalled to establish sufficient grounding of the steering components.

DVSA R/2017/28246,093 vehicles affected in the UK
🏛️ June 2017Cars built February 2014 to February 2017

Starting current limiter may overload

Where the car incurs severe engine damage resulting in the engine failing to turn over (engine seizure) and if the driver repeatedly attempts to start the engine despite the engine not cranking the very high electrical current could lead to overheating of the starting current limiter and the potential for a fire.

Put right by: Recall the vehicles that are likely to be affected and install an additional fuse in the electrical line to the starter.

DVSA R/2017/09674,444 vehicles affected in the UK
🏛️ June 2017Cars built August 2016 to March 2017

Airbag may not deploy correctly

The propellant mixing ratio in the igniters of the front passenger airbag assembly may not meet specification. If the airbag is required and activated it might not deploy or not completely deploy. This could increase the risk of injury to the occupants.

Put right by: Recall the vehicles that are likely to be affected and replace the front passenger airbag assembly.

DVSA R/2017/1771,034 vehicles affected in the UK
🏛️ June 2017Cars built April 2011 to April 2013

Vacuum line brake booster may break

The connection fitting of the vacuum line to the brake booster is not to specification and my not be durable. If the connection fails the brake booster will no longer be supplied with vacuum. After a few brake applications the driver will have to apply additional pressure to the brake pedal to gain the appropriate braking effect.

Put right by: Recall the vehicles that are likely to be affected and replace the vacuum line on the brake booster with a quality assured component.

DVSA R/2017/1794,787 vehicles affected in the UK
🏛️ June 2016

Risk of fire

A threaded connection in the Prefuse box may not be tightened to the correct specification. This may excessive resistance and create a heat source. This could cause a fire. Additionally vibration may cause power disruption which could affect the operation of steering power assistance ABS SRS and/or instrument failure..

Put right by: On affected vehicles check threaded connection and where necessary replace fuse box.

DVSA R/2016/1511 vehicles affected in the UK
🏛️ May 2016Cars built December 2012 to March 2016

Rear bench seat may lift up from the rear in a collision & attached seat belts may not be anchored correctly

On 'B' Class models fitted with 'Easy Vario' rear seat option a bolt securing the seat bench to the body may have been omitted during production. This may allow the seat bench to lift during a frontal collision. Seat belt effectiveness may also be compromised.

Put right by: On affected vehicles check for presence and tightness of retaining screws. Fit new screws where necessary and tighten all screws to specification.

DVSA R/2016/091146 vehicles affected in the UK
🏛️ January 2016Cars built October 2015 to November 2015

Risk of fire

The high pressure fuel lines have not been manufactured to the correct specification which over time can lead to crack formation and fuel leaking. Fuel escaping in the presence of an ignition source could lead to fire.

Put right by: Recall the vehicles that are likely to be affected and replace the high pressure fuel lines.

DVSA R/2015/2591,327 vehicles affected in the UK
🏛️ December 2015Cars built September 2014 to September 2015

Vehicle may cut out

In rare cases the propulsion control unit may send an incorrect message. This may cause the electric power train to shut down. Power can be restored by the normal start sequence.

Put right by: Update software on affected vehicles.

DVSA R/2015/231243 vehicles affected in the UK
🏛️ November 2015Cars built July 2015 to September 2015

Engine may fail

The camshaft could break and damage the engine due to it not being manufactured to the correct specification. If the condition occurs it will lead to a sudden loss of drive thereby increasing the risk of a collision.

Put right by: Recall the vehicles that are likely to be affected and replace the exhaust camshaft.

DVSA R/2015/210395 vehicles affected in the UK
🏛️ August 2015Cars built September 2014 to November 2014

Front passenger airbag may not deploy

Certain fuses in the passenger's footwell may not have been fitted correctly. This may adversely affect the instrument cluster windscreen wipers and the passenger seat occupancy recognition system. In certain conditions this may cause the passenger's air bag not to deploy in an accident.

Put right by: On affected vehicles check fuses and if necessary replace fuse box.

DVSA R/2015/1451,028 vehicles affected in the UK
🏛️ July 2015Cars built September 2011 to June 2013

Possibility of loss of drive

The drive shaft and the hub of the outer joint may separate. In very rare cases it cannot be excluded that the vehicle stops. The steering and braking system remain fully available to the driver.

Put right by: Recall the vehicles that are likely to be affected to replace the snap ring both sides together with the respective outboard boots on the affected vehicles.

DVSA R/2015/0993,890 vehicles affected in the UK
🏛️ January 2015Cars built February 2014 to November 2014

Oil may leak

On certain diesel engines the 'O' ring may not have been produced to the correct specification. This may allow oil to leak and contaminate the environment. If excessive oil is lost engine damage may occur.

Put right by: On affected vehicles replace the chain tensioner sealing ring.

DVSA R/2014/18261,672 vehicles affected in the UK
🏛️ July 2013Cars built January 2012 to May 2012

Rear back-rest may fail

It is possible that vehicles fitted with the Easy Vario seat system may have a seat back-rest lock that is not to specification. This could in the event of extreme loading (a rear end collision) result in the lock failing and the seat back-rest folding forward possibly causing injury to the occupant.

Put right by: Recall all affected vehicles to check and if required replace the rear back-rest lock.

DVSA R/2013/069100 vehicles affected in the UK
🏛️ May 2012Cars built February 2011 to April 2011

Transmission may not operate correctly

A frictional connection (clutch within the gearbox) may go out of tolerance and produce a chattering noise. This will be followed by a warning message appearing in the instrument cluster and symptoms similar to a slipping clutch.

Put right by: Recall the vehicles that are likely to be affected to check the thrust link belt of the continuously variable transmission. Where necessary the transmission will be replaced.

DVSA R/2012/06351 vehicles affected in the UK

Recall data published by the Driver and Vehicle Standards Agency under the Open Government Licence v3.0. A recall listed here may not apply to every car of this model: the build dates and the registration check are what decide it.

Mercedes-Benz B-Class cambelt or timing chain, and service intervals

An overdue cambelt is the most expensive thing a seller can fail to mention on a used B-Class. These are the figures UK specialists work to.

Timing belt (cambelt)Belt
1.5 DCI, 1.5 CDI, OM607, K9K
60,000 miles or 5 years, whichever comes first

Renault-sourced engine, and the engine maker's guidance is the shorter one: Renault specifies the belt at 60,000 miles or 5 years, whichever comes first, while a Mercedes dealer schedule quoted 100,000 miles / 5 years and was later revised to 124,000 miles / 10 years. The 60,000-mile Renault figure is recorded. Rubber degrades with age so the 5-year limit is the critical one.

Timing chainChain
M270, M274, 1.6 TURBO, W176, W246
No fixed replacement interval

Dual-stage chain system: an upper cam chain plus a lower oil-pump and balance-shaft chain. Cam phasers (Y49/1, Y49/2) wear from around 60,000-80,000 km giving a cold-start tick; chain and guide wear shows from about 80,000 km on urban short-trip cars but 120,000-140,000 km on motorway cars. A metallic cold-start rattle needs prompt attention. The M274 DE16 is the longitudinal C-Class version of the same 1.6.

Always confirm against the vehicle handbook. Intervals vary by engine, and several manufacturers revised theirs after failures in service.

Repair costs are typical UK ranges, not quotes. Actual cost depends on condition and garage.Data last verified: September 2026

Mercedes-Benz B-Class buying questions

What are the most common Mercedes-Benz B-Class problems?

Three stand out. Engine: timing chain stretch and leaking hydraulic tensioners on the M270 turbo petrol. Gearbox: the 722.8 Autotronic CVT's internal gearbox ECU fails (typically 27000 to 70000 miles). Electrics: the steering column clock spring breaks. The full list above is grouped by generation, with typical mileage and a rough repair cost for each.

Which Mercedes-Benz B-Class years should I avoid?

No Mercedes-Benz B-Class year is a write-off, but the W176 / W246 / C117 / X156 (2013 to 2018) carries the most serious faults: engine and electrics. The W169 / W245 (2004 to 2012) has high-severity faults on record too. Year matters less than whether the specific car has had the known fixes, so check the history for them.

What should I check when viewing a used Mercedes-Benz B-Class?

Ask the seller about the engine, gearbox and electrics faults on this page and whether they have been fixed, with invoices. On the test drive watch for metallic rattle from the engine for several seconds on cold start-up, 'Transmission Visit Workshop' warning on the dash and airbag warning light appearing on the dashboard. Read the MOT history for repeat advisories, then paste the advert into the free check, which reads it against all 4 known faults before you travel. Check a Mercedes-Benz B-Class advert →

Are there any recalls on the Mercedes-Benz B-Class?

The DVSA lists 45 safety recalls for the Mercedes-Benz B-Class issued between 2012 and 2024. The most recent, from May 2024, is "SRPC2404 - Backup function of steering software". Recall work is done by the manufacturer, and GOV.UK says you will not usually have to pay for it. This list is by model, so it cannot tell you whether one particular car has had the work: the free GOV.UK MOT history check shows a recall status from the registration where the manufacturer shares it, and a franchised dealer can check the VIN.

What is the real MPG of a Mercedes-Benz B-Class?

Owners report 46.4 mpg on average across the Mercedes-Benz B-Class engines with data, about 84% of the official combined figure. The gap between official and real-world economy varies a lot by engine, so the Real MPG page lists every engine and generation separately, from 540 owner submissions. Mercedes-Benz B-Class Real MPG by engine →

Looking at a Mercedes-Benz B-Class right now? Check the advert before you go and see it.

Where this Mercedes-Benz B-Class fault data comes from

If you used to check the Honest John “Good & Bad” section before the site closed in 2026, this page is where that information now lives. We rebuilt the Mercedes-Benz B-Class owner-report history from the archived Honest John dataset, added our own research, specialist and owner-club sources and DVSA recall data, and we keep it free. Each fault above is badged with its source. The same data feeds our free advert check, which reads a listing against every known fault for the exact engine and year.

CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services. What happened to Honest John, and where each feature lives now.

Before you go and see it

Knowing what a Mercedes-Benz B-Class goes wrong with is half of it. The rest is reading the advert and checking the car's history before you hand any money over.

How to haggle for a used car: negotiate the price with what its records show13 min readHPI check vs carVertical: which is better, and our pick for a UK car9 min readMOT advisories explained: how to check them, and which ones should worry you12 min read
All buyer's guides →

Other Mercedes-Benz models

E-Class25 known faultsC-Class23 known faultsA-Class13 known faultsSLK7 known faults