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Mercedes-Benz

S63 AMG

W221 (M156)· 2007-2010 sedan Caution

Top issues

6 known problems · 2 high

high

Cylinder head bolt failure (early M156)

Any (age-related, engines built up to about early 2010)

high

Active Body Control (ABC) suspension

Any

medium

Camshaft adjuster rattle and camshaft/lifter wear

Cold-start rattle from about 100,000 miles (160,000km) in a UK guide (unverified)

All 6 problems ↓ Inspection checklist →

Recalls

1 on record

REC-003186 2009-03-23

Defect: Long-term durability testing showed the lower ball joint of the front struts on certain S-Class (type 221) cars with ABC suspension could fracture after very high mileage on rough roads.

Hazard: Normal steering would be impaired.

Remedy: Mercedes-Benz Australia/Pacific writes to owners of affected vehicles; the notice does not describe the repair itself.

Affected: 33 units, S Class (type 221) with ABC suspension; the notice does not say which sub-models, so check S63 VINs with Mercedes-Benz (unverified)

Official notice: www.vehiclerecalls.gov.au · details checked 2026-11-09

Check a specific car by VIN at vehiclerecalls.gov.au.

At this odometer

See which of this car's known problems are due at that mileage, which should already have been dealt with, and what's coming up.

Before and after

Before: Mercedes-Benz S55 AMG (W220)

After: Mercedes-Benz S63 AMG (W221 facelift, M157 5.5L biturbo)

Price (AUD)

$31k-$53k (unverified)

Body styles

Sedan

Drivetrain

RWD

Origin

Germany

Built in

Germany

Overview

The M156 S63 AMG is the W221 S-Class with AMG's hand-built 6.2L naturally aspirated V8 (badged 6.3 for the old 6.3-litre prestige, though it is 6208cc). It reached Australia in September 2007 as a 2008 model year car at a launch price of about $350,000, so a used one is a very large car with a very expensive set of consumables. This guide covers the M156 cars only; the later S63 with the 5.5L twin-turbo M157 is a different engine with different faults. Two things decide whether one is a bargain or a bill: whether the cylinder head bolts have been replaced (early M156 engines, built up to about early 2010, are affected, per the Mercedes service bulletin summarised in the sources) and whether the Active Body Control suspension is healthy. Insist on dealer or AMG-specialist history, and budget for a pre-purchase inspection that includes a leak-down or head-bolt check and an ABC scan. Not for the faint-hearted: fuel use is around 14-15 L/100km on paper and much worse in town. Australian cars use the AU-delivered spec; UK and US figures quoted in overseas guides (518hp, £ prices) are not used here.

Engines & variants

6.2L M156 V8 (S63 AMG)

Engine

Naturally aspirated AMG V8, hand-built

Engine code

M156

Config

V8 NA

Displacement

6208cc

Power

386kW @ 6800rpm

Torque

630Nm @ 5200rpm

Drivetrain

RWD

0–100

4.6s

Economy

14.5 L/100km combined (unverified)

Transmission

7AT (AMG SPEEDSHIFT PLUS 7G-Tronic)

Timing chain / belt / gear

Chain-driven

Pros

Hand-built 386kW V8 with a real exhaust note and no turbo lag
4.6s 0-100 in a limousine-sized car
Huge depreciation: a $350k new car now costs the price of a family hatch
Full S-Class luxury kit and ride quality when the ABC is healthy

Cons

Early engines can stretch or snap cylinder head bolts, a possible engine-destroying fault
Active Body Control and air components are expensive to repair
14.5 L/100km claimed, worse in town
Dealer-level parts and labour pricing; a big brake, tyre and service bill
Tow rating not stated in the AU data we found

Known problems

high

Cylinder head bolt failure (early M156)

The torque-to-yield head bolts on early 6.2L M156 engines can stretch and snap, usually at the rear of the engine; one failure overloads the others. Coolant and oil can then enter the combustion chamber, and in severe cases the engine is destroyed. Warning signs are repeated low coolant, high oil level, a check engine light and white exhaust smoke. Mercedes bulletin LI01.30-P-051567 (April 2011) describes the repair as removing the heads, measuring piston deck height and replacing the head bolts and hydraulic tappets, and the rod, piston and bearings if deck height is out of spec.

Fix: Ask for invoices showing the head bolts and tappets were replaced to the bulletin. If there is no proof, treat it as a pending repair: get a specialist inspection (coolant pressure test, oil/coolant check) and negotiate accordingly.

Any (age-related, engines built up to about early 2010)

medium

Camshaft adjuster rattle and camshaft/lifter wear

The M156 is known for a rattle from the intake camshaft adjusters on a cold start, and for soft camshaft lobe and lifter wear. Mercedes acknowledged lifter/cam wear in service bulletin S-B 05.20/20b (2009) per an Australian guide. Overseas guides also list the camshaft adjuster solenoids as a common failure.

Fix: Listen on a cold start. Repair is adjusters/solenoids, and cams and lifters if worn, done at the same time as head work if the heads are already off.

Cold-start rattle from about 100,000 miles (160,000km) in a UK guide (unverified)

high

Active Body Control (ABC) suspension

W221 cars with ABC had an Australian recall for the front strut ball joint (see Recalls) and are prone to leaking air bellows/hydraulic components with age; a UK guide advises checking ride height at every corner, since leaks overwork the pump and let the car sink. Owner-reported: warning lights and a lowered corner are the usual signs.

Fix: Check ride height on all four corners after the car has stood overnight, scan for ABC faults, and confirm both recalls were done. Budget for strut and pump work.

Any

medium

7G-Tronic shift quality (valve body / conductor plate)

A UK guide says shifts were not always smooth on pre-facelift cars, linked to the valve body and conductor plate electronics of the 7G-Tronic.

Fix: Test cold and hot, including kickdown and manual paddle shifts. Repair is a conductor plate or valve body service at a transmission specialist.

Any

low

Oil leaks and breather faults

UK guide: valve cover, camshaft solenoid cover and oil filter housing gaskets leak, the crankcase breather valve diaphragm and hose deteriorate, and the magnesium intake manifold and idler pulley can fail.

Fix: Look for seepage around the valley and filter housing, and check for misfires (coils and ignition module are common causes).

Age-related

low

Parking brake switch and small electrical faults

Owner-reported (Australian and UK guides): a faulty parking brake switch triggers a dash warning and brake failure message; intermittent A/C from a fan/blower fault and sunroof wind noise from a failed seal also appear, plus control-module electrical faults generally.

Fix: Check every warning light, A/C and sunroof operation on test drive. Brake discs and pads are large and costly, so inspect them.

Any

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