Mercedes-Benz B 200 CDI
Robust two-litre diesel with common rail. Known for leaking injector seals and DPF issues under short-trip use. Otherwise long-lived.
Comfort Diesel
With automatic and 103 kW, the B-Class diesel is a pleasant daily companion — for pragmatic families.
Engine Weaknesses 6
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
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
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
The diesel particulate filter on the OM640 does not regenerate adequately during short-trip driving. Insufficient exhaust temperatures leave soot in the filter and block it.
Symptoms: DPF warning light, power loss, elevated fuel consumption, engine enters limp mode
The DMF on the OM640 in the A180/B180 CDI is known for premature wear. Mercedes acknowledged the problem and announced an improved version.
Symptoms: Loud rattling from engine bay when warm, noise disappears when pressing the clutch, vibrations when pulling away and manoeuvring
The oil cooler on the OM640 is prone to leaking gaskets at the oil filter housing. Oil traces on the heat shield under the engine. Gasket replacement resolves the issue.
Symptoms: Oil spots on underbody cladding, oil smell after shutdown, dropping oil level without visible external leak
Vehicle Weaknesses 7
Early rust starts at door lower edges and spreads to bonnet and strut tops. Vehicles only 3 years old already show initial rust. Typical problem of early model years.
The CVT gearbox (Autotronic) is prone to failure of the chain link belt, pressure sensors and control unit. Repair costs €3,300–3,400, rarely economical. Oil change every 60,000 km is mandatory.
Driveshaft gaiters become leaky prematurely; without immediate repair the shafts break completely. MOT regularly flags driveshafts and steering joints. Replacement costs €430–650.
Vehicles before the 2008 facelift show pronounced corrosion on lower door edges, bonnet and strut tower mounts. Mercedes carried out goodwill repairs.
As with the related W169, A/C condensers lose refrigerant through defective solder joints. A/C fails at higher temperatures. Replacement requires engine bay disassembly.
Rear leaf springs break unexpectedly; Mercedes is cooperative on replacement. Brake lines also rust and are flagged at MOT. Park sensor cables deteriorate prematurely.
The central display in the instrument cluster dims heavily in warmth or fails completely. The defect often cannot be permanently resolved by software updates.