Mercedes/M157

Mercedes · Engine

M157

E63 AMG·W212·2011–2016

"Currently getting a new timing chain and tensioner from mildly extended crank time — at approx 70k miles."

RISKY

55/ 100

"Fast, expensive, and unforgiving to neglect"

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Max HP

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Torque Nm

10,000

Oil interval km

Recalls

Known issues

Known Issues

Timing Chain Stretch and Tensioner Failure€2,500-6,000 · 70,000-130,000 kmCRITICAL

The M157 timing chain and tensioners are known to wear and stretch prematurely, particularly when oil changes are delayed or the engine is started cold and revved quickly. Extended crank times are an early warning sign. Failure to address this can lead to catastrophic engine damage.

Extended crank time before start

Rattling noise on cold start

Check engine light

Rough idle on startup

DIY: Expert only

Engine Oil Leaks (Front and Rear Seals)€800-2,500 · 80,000-160,000 kmHIGH

Multiple forum reports confirm oil leaks on the M157, particularly from the front of the engine. Valve cover gaskets, camshaft seals, and front main seals are common culprits. Oil leaks can lead to scoring if left unaddressed.

Oil spots under parked car

Oil smell from engine bay

Visible oil residue on front of engine

Low oil level without smoke

DIY: Hard

Engine Scoring from Oil Starvation€5,000-15,000 · 100,000-200,000 kmHIGH

The M157 and related M278 platforms have shown instances of engine cylinder scoring, particularly on heavier vehicles. This is associated with oil quality degradation or extended oil change intervals. Once scoring occurs, the repair cost is severe.

Loss of compression

Excessive oil consumption

Knocking or ticking from engine internals

Blue smoke on acceleration

DIY: Expert only

Camshaft Position Sensor Failure€200-600 · 60,000-120,000 kmMODERATE

The camshaft position sensors on the M157 are a known fault point, widely reported in the community. Failure can cause rough running, misfires, or a no-start condition. Replacement is relatively affordable compared to other M157 issues.

Rough idle

Misfires

Check engine light with cam sensor codes

Hesitation on acceleration

DIY: Moderate

Spark Plug Wear and Indexing Requirements€300-700 · 40,000-80,000 kmLOW

Forum discussions highlight that spark plug replacement on the M157 requires careful indexing for optimal performance. Incorrect installation can cause running issues. Labour access is difficult given the engine layout.

Rough idle

Slight misfires

Reduced performance

Increased fuel consumption

DIY: Hard

Buying Checklist

Cold-start the engine and listen carefully for timing chain rattle in the first 5–10 seconds

Request a full documented service history proving oil changes at or below 10,000 km intervals with approved spec oil

Inspect the front and underside of the engine thoroughly for any signs of oil leaks or fresh sealant

Perform an OBD-II scan for fault codes, specifically targeting camshaft sensor and timing-related codes

Verify the timing chain and tensioners have been replaced or confirm their condition via specialist inspection

Have an independent AMG-specialist mechanic perform a pre-purchase inspection before committing to purchase

Service Reality

Community oil interval10,000 km

Oil specificationMercedes-Benz 229.5 or 229.51, 0W-40 or 5W-40 fully synthetic

Est. ownership cost (2yr)€3,000–7,000 per year depending on maintenance history and whether deferred repairs are inherited at purchase

Real mix fuel consumptionNo data

Also Found In

Mercedes-Benz S63 AMG (W221/W222)Mercedes-Benz CLS63 AMG (W218)Mercedes-Benz GL63 AMG (X166)Mercedes-Benz G63 AMG (W463)Mercedes-Benz SL63 AMG (R231)Mercedes-Benz ML63 AMG (W166)

Buying Advice

The Mercedes M157 is a spectacular engine that demands respect and meticulous maintenance — buy one with poor service history and you are inheriting someone else's time bomb. Timing chain issues appear before 100,000 km and oil leaks are common, so factor in a significant maintenance buffer of at least €3,000-5,000 post-purchase. Only buy from a seller who can provide proof of regular short-interval oil changes and ideally evidence of timing chain inspection or replacement. This engine rewards informed, committed owners and punishes anyone who treats it like a normal car.

Parts People Buy

M157 Timing Chain KitLink unavailable

M157 Camshaft Position SensorsLink unavailable

M157 Oil Filter KitLink unavailable

M157 Valve Cover Gasket SetLink unavailable

OBD-II Diagnostic Scanner Mercedes AMGLink unavailable