"Is the B Serisi B 200 CDI 7G-DCT reliable, and what should you check?"
When buying a used Mercedes-Benz B-Class 1.8 CDI 2012 (246), the most frequently mentioned issue is: Abnormal CVT Automatic Transmission Behavior. Turbocharger problems are also commonly reported.
Engine: OM651
OM651.901 · diesel · B 200 CDI 7G-DCT · Used in this car from 2011-2014
Strengths
Decent lifespan with proper maintenance
Modest fuel consumption for such power
Watch-outs
Finicky Delphi fuel system
Frequent bearing shell rotation
Low timing chain tensioner lifespan
Known engine issues
Fuel systemUntil 2011, main versions used Delphi fuel system with piezo injectors prone to leaks, often causing hydraulic lock and piston burn-through. A recall was even issued to replace them with simpler electromagnetic ones. Engine modifications with Bosch fuel system have no reliability issues.
Bearing shell rotationMany owners of vehicles with this diesel have encountered bearing shell rotation. The cause is dilution of overheated oil due to clogged heat exchanger or oil pressure drop from variable displacement oil pump failure. The engine also lacks a standard oil pressure sensor, but one can be installed.
Timing chain hydraulic tensionerThe combined timing drive consists of a roller chain and several gears. The chain can last up to 300,000 km, but its hydraulic tensioner often fails much earlier, and replacing it is quite labor-intensive and expensive.
Listed from most frequently reported, each with its source.
Abnormal CVT Automatic Transmission Behavior
Often reported
Some B-Class W245 models with CVT transmissions report delayed gear shifts (especially reverse and sometimes D), jerky initial engagement when pressing the accelerator during delay, and rough shift feel.
Transmission
Turbocharger Problems
Often reported
W245 era 2.0 CDI diesel engines report power loss, exhaust smoke, and abnormal noises from the turbocharger.
Turbo
Mercedes-Benz B Serisi B 200 CDI 7G-DCT technical specs
Mercedes-Benz B Serisi B 200 CDI 7G-DCT (2012): boot 488 L; fuel use 4,2 l/100 km (urban 4,9 l/100 km · extra-urban 3,9 l/100 km); 0–100 in 9.3 s.
Boot capacity
488 L
Fuel consumption
4,2 l/100 km (urban 4,9 l/100 km · extra-urban 3,9 l/100 km)
What to look for when buying a Mercedes-Benz B-Class 1.8 CDI?+
When buying a 2012 model 1.8 CDI, check the service history, test drive, and engine/transmission warnings. Most commonly reported issues: Abnormal CVT Automatic Transmission Behavior; Turbocharger problems.
What are the chronic problems of the Mercedes-Benz B-Class 1.8 CDI?+
Instead of a simple yes/no, it's better to weigh the proven pros and cons together. This page lists 2 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from European fault records records; the source vehicle and target vehicle are verified for brand, fuel, engine, and generation compatibility. Topics with insufficient evidence are not shown.
We only publish claims we can verify. Cards come from European fault records and owner reports matched to this vehicle on brand, fuel, engine and generation.
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