Timing chain kit M278 for Mercedes-Benz

OE spec timing chain kit, engineered for Mercedes Benz vehicles with the M278 4.7 V8 biturbo engine. Restores precise valve timing, quiet starts and reliable performance after chain stretch or guide wear. Sold per kit, variant specific to engine code and year.

What this is / isn’t:
Included: Primary timing chain, fixed and pivot guides, hydraulic tensioner, guide pins or rails, front cover seal or gasket where supplied.

Important: Match by VIN and engine code M278. Early and late M278 units can use different guide designs, tensioners and chain specs. Not for AMG 63 models that use M157 or later M177 engines. Always confirm by OE number.

Key Features:

• OE matched geometry: Correct chain pitch and guide profile for accurate cam timing.

• Quiet operation: Hardened pins and low friction guide faces reduce start up rattle.

• Stable tension control: Calibrated hydraulic tensioner maintains chain load across rpm and temperature.

• Leak resistant service: New front cover seal or gasket where supplied to help prevent seepage after reassembly.

• Exact fitment: Direct replacement parts for a no mod install when used with factory timing tools.

Compatibility:
Common Mercedes models with M278 V8 biturbo, confirm by VIN or OE:

• S Class W221 late, W222 early S500, S550

• E Class W212 E500, E550

• CLS C218, X218 CLS500, CLS550

• ML W166, GLE W166 ML500, ML550, GLE500 where fitted

• GL X166, GLS X166 GL500, GLS500, GLS550

• G Class W463 select markets G500, G550
  Markets and years vary, match by VIN.

Typical OE reference families, guide only:
A278 050 … timing chain, A278 052 … tensioner, A278 052 … guides and rails, with supersessions by year and market.
Always order by the exact OE part number on your vehicle or confirm via VIN.

When to replace a timing chain kit:

• Rattle at cold start or warm idle, chain slap from the timing cover

• Fault codes for cam crank correlation, P0016, P0017, or cam adjustment range errors

• Retarded cam timing on scan data, rough running, poor fuel economy

• Metal debris in the oil filter, guide material found during service

Installation notes, pro tips:

• Use correct crank and cam locking tools, follow factory timing marks and torque specs.

• Replace single use fasteners, crank bolt and cam bolts where specified.

• Clean sealing faces, apply approved sealant to the front cover, allow proper cure time.

• Change engine oil and filter after repair, use Mercedes approved oil, MB 229.x spec.

• Clear adaptations with a scan tool, road test, recheck for leaks and stored faults.

What’s included, not included:
✅ Timing chain, guides and hydraulic tensioner, front cover seal or gasket where supplied
❌ Oil, sealant, crank bolt, cam phasers, water pump, belts, auxiliary hardware unless listed

Q&A
Q1: Will this fit AMG 63 models?
No, AMG 63 uses M157 or M177 engines, parts differ. Match by VIN and engine code.
Q2: Does this fix the cold start rattle?
Yes, when caused by chain stretch or worn guides. Correct tensioner and precise timing setup are essential.
Q3: Do I need special tools?
Yes, cam and crank locking tools and a torque angle gauge are required to set timing accurately.
Q4: Can I reuse the crankshaft bolt?
Not advised, it is usually torque to yield, replace with new where specified.

Why choose TOParts:
OE grade engine kits for Mercedes Benz with precise fitment, correct materials and proven durability, trusted by panel shops and independent Mercedes specialists across South Africa.