"Is the S Serisi S400 reliable, and what should you check?"
When buying a used Mercedes-Benz S-Class S400 2014 (217 / 222), the most frequently mentioned issue: Oil leaks from cylinder head plugs and gaskets. Also, Ignition Misfires: Ignition Coils, Injectors and Sensors are commonly reported.
Engine: M276
M276.960 · turbo petrol · S400 · Used in this car from 2014-2014
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.
Oil leaks from cylinder head plugs and gaskets
Often reported
A frequently reported issue is oil leaks around plastic cylinder head plugs and valve cover gaskets. Over time, these parts can harden or crack, causing visible leaks and sometimes smoke or a burning oil smell.
Engine Bay
Ignition Misfires: Ignition Coils, Injectors and Sensors
Often reported
Over the years, misfires due to worn ignition coils, faulty spark plugs/injectors, or sensors (e.g., MAF, lambda) are common; this leads to warning lights, rough idle, and power loss.
Engine Internal
Oil consumption and risk of cylinder damage
Often reported
Many users and technical reports indicate higher than normal oil consumption in high-mileage vehicles; if not monitored, it can worsen cylinder wall wear or 'cylinder scoring', especially when combined with intake manifold deposits.
Engine Internal
Timing chain and gear wear
Often reported
In the M273 V8 engine, the timing chain, tensioners, and gears can wear prematurely; this can cause rattling noise, warning light, and timing loss.
Timing chain
Mercedes-Benz S Serisi S400 technical specs
Mercedes-Benz S Serisi S400 (2014): boot 510 L; fuel use 6,8 l/100 km (urban 7,4 l/100 km · extra-urban 6,5 l/100 km); 0–100 in 6.8 s.
Boot capacity
510 L
Fuel consumption
6,8 l/100 km (urban 7,4 l/100 km · extra-urban 6,5 l/100 km)
What to look for when buying a Mercedes-Benz S-Class S400?+
When buying a 2014 S400, check service history, test drive, and engine/transmission warnings. Most commonly reported issues: oil leaks from cylinder head plugs and gaskets; Ignition Misfires: Ignition Coils, Injectors and Sensors; oil consumption and risk of cylinder damage.
What are the chronic problems of the Mercedes-Benz S-Class S400?+
Most commonly reported issues: oil leaks from cylinder head plugs and gaskets; Ignition Misfires: Ignition Coils, Injectors and Sensors; oil consumption and risk of cylinder damage.
Is the Mercedes-Benz S-Class S400 reliable?+
Rather than a simple yes/no, it is necessary to evaluate 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 Difetti fault database records; compatibility of brand, fuel, engine, and generation between source and target vehicle is verified. Topics with insufficient evidence are not shown.