KNOWN FAULTS · Mercedes-Benz

Known faults for the Mercedes-Benz Clase B (W246).

2011–2018 · Petrol / Diesel

Sources are not verified in real time and no entry confirms that your car is affected.

3 known faults with sources

Engines: B 180 / 200 (M270) (Petrol)

M270/M274 chain, adjusters and thermostatTiming / leaks

Engine / equipment: M270 and M274 1.6/2.0 turbo petrol (A, B, CLA, GLA, C, E, GLC, SLC)
Period mentioned: 2012–2020
Symptoms: Chain rattle on cold starts; engine light with camshaft timing codes (for example P0016 or P001685); oil leaks at the camshaft adjusters; slow coolant loss.
Possible cause described: The hydraulic tensioner loses pressure overnight and the plastic guides wear, especially with long oil change intervals. The camshaft adjuster magnets leak oil (common between 65,000 and 110,000 km) and the plastic thermostat housing cracks.
Check for the garage: Listen to a cold start, read camshaft codes, look for oil on the adjuster magnets and coolant residue at the thermostat. Use Mercedes 229.5 oil.
Cost cited in the source: Chain and tensioner: approx. €320–1,650 (converted from dollars)A rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 65,000–110,000 km. This is not a maintenance interval and does not predict a failure.

Engines: B 160 / 180 CDI (1.5, OM607) (Diesel)

Renault 1.5 diesel (OM607/OM608) injectors, EGR and DPFInjection / EGR / DPF

Engine / equipment: OM607 and OM608 1.5 diesel of Renault origin (K9K): A 160/180 CDI and d, B 160/180, CLA 180 CDI and d, GLA 180 d, Citan
Period mentioned: 2012–2026
Symptoms: Smoke, hesitation or hard starting (injectors); unstable idle, power loss and engine light (EGR); particulate filter warning in town use; oil consumption.
Possible cause described: It is Renault's 1.5 dCi with Mercedes electronics. On the OM607 the injectors are the main weak point; the OM608 that replaced it in 2018 has fewer problems. The EGR builds up carbon, mostly between 60,000 and 100,000 km, and the particulate filter clogs on short trips.
Check for the garage: Identify the engine (OM607 until 2018, OM608 after), measure injector balance rates, check the EGR and particulate filter status and watch the oil level.
Cost cited in the source: Depends on the part (injectors, EGR or turbo); the sources consulted give no reliable figuresA rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 60,000–100,000 km. This is not a maintenance interval and does not predict a failure.

Engines: B 180 / 200 / 220 CDI (2.1, OM651) (Diesel)

Chain, injectors and coolant leaksTiming / injection

Engine / equipment: OM651 2.1/2.2 CDI (C 200/220/250 CDI, E 200/220/250, GLK, Vito, Sprinter)
Period mentioned: 2008 onwards
Symptoms: Chain rattle on a cold start; on early units, loud injector knocking; coolant loss from the plastic coolant manifold or the EGR cooler.
Possible cause described: Plastic chain guide and a hydraulic tensioner that loses pressure (the chain is at the rear). Early units used problematic piezo injectors that Mercedes replaced in a campaign.
Check for the garage: Listen to a cold start, check the dealer's injector campaign history and check the coolant level.
Cost cited in the source: Chain: approx. €1,500–3,000 (estimate)A rough figure from the original database, not an up-to-date quote.