Mercedes-Benz

CLK63 AMG C209 / A209 inspection checklist

2006-2009 · 4 things to check before you buy, taken from this car's known problems.

This car

highM156 cylinder head bolt failure

Look for: 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 and other M156 cars. Whether a given car has been updated is not shown by the build date alone.

If you find it: 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.

Any (age-related, not a fixed distance)

highCamshaft lobe and hydraulic lifter wear

Look for: 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.

If you find it: 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.

Owner-reported from about 160,000km

mediumCamshaft adjuster rattle

Look for: 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.

If you find it: Listen on a cold start. Replacement of the adjusters (and normally the related solenoid seals) is the repair.

mediumOil leaks and crankcase breather

Look for: 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.

If you find it: 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.

From FlamingCars' Mercedes-Benz CLK63 AMG guide. It's a checklist of known problems, not a replacement for a professional pre-purchase inspection. Your ticks are kept in this browser only.