Mercedes-Benz CLS 63 AMG Shooting Brake
5.5-litre V8 BiTurbo — AMG's first forced-induction V8 and the successor to the naturally aspirated M156. 525–585 hp depending on model, up to 900 Nm in the S version. The character is fundamentally different from the M156: instead of a high-revving scream, a brutal torque wave from 1,750 rpm. The sound is deeper, more bass-heavy, with a characteristic turbo hiss on lift-off. Less emotional than the naturally aspirated engine, but in a different league on the motorway — above 200 km/h the M157 still accelerates like others do at 100. Timing chain is the known Achilles heel: chain tensioner failure at 80,000–120,000 km, Mercedes has improved the design (non-return valve in cylinder head oil gallery). Piezo injectors are sensitive to fuel quality, service life 100,000–150,000 km. Turbos last 200,000+ km with proper warm-up and cool-down — shut off immediately after a motorway run and they'll fail significantly earlier. Warm up the engine, allow cool-down after hard use, oil changes every 10,000 km with 0W-40 — then 300,000 km is realistic.
Shooting Brake — V8 BiTurbo in the Prettiest Estate
CLS 63 AMG Shooting Brake X218: 525 hp in the rarest and most beautiful M157 vehicle. Fewer than a handful on the market at any one time — genuine rarity value. The combination of design icon and BiTurbo V8 makes the Shooting Brake the most emotionally engaging M157 application for pragmatists. Arriving at any appointment as the most interesting person in the room. The sloping roofline costs boot space.
Engine Weaknesses 11
The timing chains on the M157 5.5L BiTurbo V8 stretch, especially on vehicles with frequent cold starts and short trips. Engine damage possible if chain jumps. Extensive repair on the V8.
Symptoms: Metallic rattling on cold start, camshaft position fault codes, rough running, in extreme cases engine damage
Under heavy use the piston rings on the M157 wear prematurely. Oil consumption above 1 L/1,000 km is possible. Engine overhaul required with advanced wear.
Symptoms: Rising oil consumption, blue smoke on acceleration, oil mist from exhaust, oil level warnings
The high-pressure fuel pump on the M157 can wear internally at high mileage. Pressure drop in the rail causes difficult starting and power loss.
Symptoms: Difficult starting, power loss under load, hesitation at high rpm, fuel pressure fault codes
The M157 is affected by known timing chain wear from 80,000–120,000 km. Mercedes retrofitted check valves in the oil supply passages (TSB LI05.20-P-057028).
Symptoms: Rattling on cold start, later also at idle, check engine light with camshaft fault codes, power loss
The oil pump gear on the M157 wears at high rpm and generates metal debris. Oil pressure drop leads to overheating and cylinder bore damage.
Symptoms: Oil pressure warning at high rpm, metallic knocking from lower engine, heavy oil consumption
Timing chain and tensioners wear prematurely, especially model years 2011–2013. Mercedes retrofitted a check valve in the oil passages of the cylinder head. Repair often in the four-figure range, worst case five figures.
Symptoms: Rattling on cold start, later also at idle, increased on acceleration; check engine light
The valve cover gaskets on the M157 V8 leak and allow oil to drip onto the hot turbochargers. Smoke and a burning smell are the result.
Symptoms: Oil smell and smoke from engine bay, oil drops visible on turbochargers, dropping oil level
The M157 uses Bosch piezo injectors that typically last 100,000–150,000 km. Aftermarket alternatives are not available.
Symptoms: Rough engine, uneven idle, elevated fuel consumption, individual cylinder fault codes
Electric auxiliary water pump for charge air cooling fails. Leads to reduced power in limp mode.
Symptoms: Power loss under high load, warning message on display, limp mode
Bosch piezo-ceramic injectors are sensitive to fuel quality and have a limited service life of approx. 100,000–150,000 km. Replacing all 8 injectors costs up to 3,000 EUR; repair is not possible.
Symptoms: Rough running, misfires, power loss, check engine light, poor cold-start behaviour
The wastegate flaps on both turbochargers rattle at cold start due to play in the linkages. Usually an acoustic issue only, rarely performance-related.
Symptoms: Metallic clattering on cold start for 1–2 minutes, disappears at operating temperature
Vehicle Weaknesses 7
Differential develops play — documented even at low mileages below 20,000 km. Replacement required; covered under warranty.
Battery discharges during standstill periods of a few days. Quiescent current drain in the electronics — COMAND system or telephone module often responsible.
AIRMATIC struts lose air — vehicle sits crooked or too low after standing. Same technology as W212, same susceptibility. Individual strut 800–1,200 EUR.
A/C compressor fails — especially higher load on vehicles with auxiliary climate control. Replacement including recharge 1,000–1,800 EUR.
Brake pads squeal persistently on many C218 — repeated replacements do not solve the problem. Particularly pronounced on the large AMG brake systems due to design.
The speakers of the optional Harman/Kardon system develop rattling — especially at low frequencies and on poor road surfaces. The speaker housing mountings loosen.
The wide 285-section rear tyres on many CLS models wear excessively quickly — often within 15,000–20,000 km. Check toe and camber alignment.
