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Top issues
5 known problems · 2 high
high
M156 cylinder head bolt failure
high
Camshaft lobe and hydraulic lifter wear
medium
Camshaft adjuster rattle
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 CLS55 AMG (C219, supercharged 5.4L V8)
After: Mercedes-Benz CLS63 AMG (C218, 5.5L biturbo M157 V8, a different engine, not covered here)
Price (AUD)
$20k-$25k (unverified)
Body styles
Sedan (4-door coupe)
Drivetrain
RWD
Origin
Germany
Built in
Germany
Overview
Replaced the CLS55 AMG from October 2006 with AMG's hand-built naturally aspirated 6.2L M156 V8 (badged 6.3). It runs air springs (AIRMATIC DC) all round, so there is a second big-bill system besides the engine: rear air springs, compressor and height sensors are common failure points on these cars. An updated C219.II reached Australia in May 2008. The C219 line continued in Australia into 2011; we could not confirm exactly when the last CLS63 was sold here. Sensotronic Brake Control (SBC) was fitted to some W211/C219-era Mercedes and was the subject of 2004-2005 recalls, but we could not confirm it on the CLS63 AMG, so no SBC claim is made: ask a Mercedes dealer to confirm the brake system by VIN. The later C218 CLS63 uses a different engine and is not this guide. Real-world fuel use is near 13.4 to 14.5 L/100km.
Engines & variants
6.2L M156 V8 (CLS63 AMG)
Engine
All-alloy naturally aspirated V8, marketed as 6.3
Engine code
Config
V8 NA
Displacement
6208cc
Power
378kW @ 6800rpm
Torque
630Nm
Drivetrain
RWD
0–100
4.5s
Economy
14.5 L/100km combined
Transmission
7AT (AMG Speedshift 7G-Tronic)
Pros
- 378kW naturally aspirated V8 with big torque
- Genuinely practical four-door body with an 80L tank
- Air suspension gives a comfortable ride
- Cheaper to buy now than the engine's reputation suggests
Cons
- M156 head bolt and cam wear risks
- Air suspension repairs add to running costs
- Thirsty: about 14.5 L/100km claimed, 22.6 city
- Rear headroom is tight for a sedan
Known problems
high
M156 cylinder head bolt failure
Documented M156 fault on early engines: the original head bolts can corrode or stretch and break, letting coolant into the oil or combustion chamber. Reported warning signs are a low coolant light, misfires and a check-engine lamp. A broken bolt loads the others, so failure can cascade. Enthusiast and parts-supplier sources put the affected engines as those below engine number ending 60 060658 (roughly 2006 to early 2010 builds), and an Australian reference site lists head bolt failure for the CLS63 AMG. Whether a given car has been updated is not shown by the build date alone.
Fix: Ask for invoices showing the head bolts were replaced with the updated bolts. If there is no proof, budget for the job or have an M156 specialist check coolant loss, oil condition and compression before buying.
high
Camshaft lobe and hydraulic lifter wear
Owner-reported: the cam lobes (intake side most often) wear against the hydraulic lifters, and the cams are reported to be softer than the lifters. Reports put it from about 100,000 miles (about 160,000km), worse with long oil-change intervals. A US class action alleges defective cam and lifter material; those are allegations only. An Australian reference site also lists camshaft lobe and valve lifter wear for the CLS version of this engine.
Fix: Ask for a full service history with short oil intervals. Have a specialist pull a valve cover to inspect the lobes. Repair means replacing camshafts and lifters, usually at the same time.
medium
Camshaft adjuster rattle
Owner-reported: the camshaft adjusters (intake worst) lose hydraulic pressure and rattle at cold start, then at any revs. A service bulletin is said to cover it.
Fix: Listen on a cold start. Replacement of the adjusters (and normally the related solenoid seals) is the repair.
medium
Oil leaks and crankcase breather
Owner-reported / parts-supplier sourced: valve cover, cam solenoid cover and oil filter housing gaskets commonly leak, and the crankcase breather diaphragm or hose can deteriorate, causing oil burning, misfires, smoke and fuel-trim codes. Leaks can contaminate the alternator, belt and hoses.
Fix: Check for oil around the valve covers and filter housing; replace gaskets as a set and fit a breather valve kit if there are symptoms.
medium
AIRMATIC air suspension leaks and rear sag
Owner-reported: air springs, height sensors or the compressor (reported to fail from a degraded electrical connector) let the car sink at one or both ends, often overnight, with a suspension malfunction message. Single-owner reports, not a documented rate.
Fix: Park the car overnight and check ride height in the morning. Ask for evidence of the air bags and compressor being replaced and scan for stored suspension faults.