"Is the C Serisi C400 reliable, and what should you check?"
When buying a used Mercedes-Benz C-Class C400 2019 (205 / facelift), the most frequently mentioned issue is carbon buildup on intake valves. Additionally, oil leaks from the timing chain cover/gaskets are also commonly reported.
Engine: M276
M276.823 · turbo petrol · C400 · Used in this car from 2014-2023
Known engine issues
Timing chain tensioners are the most problematicThe most problematic part of this engine is the timing chain tensioners. If their failure is missed, the entire timing set with camshaft adjusters will need replacement.
Camshaft pulse discs may shiftOn these engines, the pulse discs on the camshafts often shift out of position.
Direct injection injectors are fuel-quality sensitiveThe direct injection injectors are sensitive to fuel quality.
+1 more issues on the engine detail page
Known issues and risks
Listed from most frequently reported, each with its source.
Carbon buildup on intake valves
Often reported
On direct injection engines like the M276, carbon buildup can occur on intake valves over time, leading to reduced efficiency, hesitation during acceleration, and rough running.
Engine Internal
Oil leaks from timing chain cover/gaskets
Often reported
Oil leaks around the timing chain cover and gaskets can cause intermittent oil consumption and require costly removal of the cover for repair.
Engine Internal
Timing chain tensioner wear
Often reported
On the V6 M276 engine, timing chain tensioners may experience wear or failure. This can cause rattling noises on cold start or at idle, and if left unchecked, risk of chain skipping.
Timing chain
Turbocharger issues and boost leaks
Often reported
The V6 biturbo in the W205 can experience turbo system problems: leaks in intercooler/intake manifold pipes, turbo actuator or seal wear can cause power loss, check engine light, and low boost codes.
Turbo
Mercedes-Benz C Serisi C400 technical specs
Mercedes-Benz C Serisi C400 (2019): fuel use 8,2 l/100 km (urban 11,2 l/100 km · extra-urban 6,4 l/100 km); 0–100 in 4.9 s.
Fuel consumption
8,2 l/100 km (urban 11,2 l/100 km · extra-urban 6,4 l/100 km)
What should I look for when buying a Mercedes-Benz C-Class C400?+
When buying a 2019 C400, check the service history, perform a test drive, and inspect engine/transmission warnings. The most commonly reported issues are: carbon buildup on intake valves; oil leaks from the timing chain cover/gaskets; timing chain tensioner wear.
What are the common problems of the Mercedes-Benz C-Class C400?+
The most frequently reported issues are: carbon buildup on intake valves; oil leaks from the timing chain cover/gaskets; timing chain tensioner wear.
Is the Mercedes-Benz C-Class C400 reliable?+
Rather than a simple yes or no, it's best to weigh the proven pros and cons together. This page lists 4 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from the Difetti fault database; the source vehicle is matched to the target vehicle by brand, fuel type, engine, and generation. Topics with insufficient evidence are not displayed.