Mercedes-Benz C 350 W204 — Reliability

W204 Sedan Mid 2007–2014 2 engines

Reliability Summary

Best engine M276 — 83/100 BUY
Worst engine M272 — 65/100 CAUTION
Average reliability 74/100

Engine Comparison

Engine Reliability Score Verdict Known Issues
M276
V6 3.0/3.5L 		83/100 BUY Secondary timing-chain tensioners drain — cold-start rattle, chain stretch (early engines) +2
M272
V6 NA 2.5-3.5L 		65/100 CAUTION Balance-shaft sprocket wear (early engines, US settlement) +5

Engines in this model

BUY 83

M276

V6 3.0/3.5L

The V6 that replaced the troubled M272: a 3.5 without turbos and a 3.0 or 3.5 biturbo, in the C, E, ...

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CAUTION 65

M272

V6 NA 2.5-3.5L

Smooth, refined V6 (2.5, 3.0, 3.5 and 3.5 CGI) in the C, E, CLK, CLS, SLK, SL, ML, R and GLK of 2004...

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Known Issues Across All Engines

Issue Engine Severity Onset
Secondary timing-chain tensioners drain — cold-start rattle, chain stretch (early engines) M276 moderate —
Valve cover / cam cover oil leaks M276 minor 100,000 km – 200,000 km
Spark plugs + ignition coils M276 minor 80,000 km – 150,000 km
Balance-shaft sprocket wear (early engines, US settlement) M272 critical 60,000 km – 140,000 km
Intake manifold flap linkage breakage M272 moderate —
High-pressure fuel pump failure (CGI direct injection only) M272 moderate —
Map-controlled thermostat failure M272 minor —
Camshaft adjuster magnet oil leak (oil wicking into the harness) M272 minor —
Spark plugs + ignition coils M272 minor 80,000 km – 150,000 km

FAQ

Is the Mercedes-Benz C 350 reliable?

The Mercedes-Benz C 350 has 2 engine options with reliability scores ranging from 65/100 (CAUTION) to 83/100 (BUY). Average reliability: 74/100.

Which Mercedes-Benz C 350 engine is most reliable?

The M276 is the most reliable engine in the Mercedes-Benz C 350, scoring 83/100 (BUY).

What problems does the Mercedes-Benz C 350 have?

Across all engine variants, the Mercedes-Benz C 350 has 9 known issues. The most common are related to Secondary timing-chain tensioners drain — cold-start rattle, chain stretch (early engines), Valve cover / cam cover oil leaks, Spark plugs + ignition coils.