2012 MERCEDES-BENZ S63 AMG

Typical onset: 40,000-80,000 mi

Symptoms: Excessive oil consumption (quart every 500-1000 miles), Blue smoke on cold start or acceleration, Loss of power and rough idle, Check engine light with misfire codes, Metallic knocking noise (rod bearing failure after oil starvation)

Fix: M157 engines suffer from defective piston ring design that causes oil burning, carbon buildup, and eventual bearing failure. Fix requires complete engine rebuild or short block replacement (preferred). 35-50 labor hours depending on whether you pull the engine. Many shops recommend OEM updated pistons/rings or aftermarket forged internals if going this deep. This is THE known issue on early M157 engines.

Estimated cost: $18,000-35,000

Typical onset: 60,000-100,000 mi

Symptoms: Transmission fluid in coolant reservoir (pink/milky coolant), Coolant in transmission pan (spotted during service), Transmission slipping or erratic shifting, Overheating transmission temperature warnings

Fix: The internal cooler inside the radiator fails and allows transmission fluid and coolant to mix—kills the transmission if not caught early. Requires radiator replacement, complete transmission fluid flush (multiple times), and often transmission replacement if contamination progressed. 8-12 hours for cooler/radiator and flushes; add 20-25 hours if transmission is damaged.

Estimated cost: $2,500-4,000 (cooler only), $12,000-18,000 (if transmission damaged)

Typical onset: 50,000-90,000 mi

Symptoms: Clunking when shifting from Park to Drive/Reverse, Vibration through chassis at idle in gear, Excessive movement felt during hard acceleration, Visible fluid leak from mount (hydraulic type)

Fix: The hydraulic transmission mount deteriorates and loses damping capability. Relatively straightforward replacement but requires supporting the transmission properly. 2-3 hours labor. Use OEM or quality aftermarket (Lemförder)—cheap mounts fail quickly.

Estimated cost: $600-1,200

Typical onset: 70,000-120,000 mi

Symptoms: "ABC malfunction, vehicle rising" warning message, Car sitting low on one corner after sitting overnight, Hydraulic fluid puddles under vehicle (green fluid), Rough ride quality or suspension knocking noises, Pump running continuously

Fix: ABC struts, lines, and valve blocks develop leaks. The front struts are most common ($2,500-3,500 each, 4-5 hours per corner). Valve block leaks run $3,000-5,000 (8-10 hours). Pressure hoses $800-1,500 (2-4 hours depending on location). The ABC pump itself can fail ($2,500-4,000, 6-8 hours). This system is expensive to maintain—plan on $2,000-5,000 every 50k miles for something ABC-related.

Estimated cost: $1,500-8,000 depending on component

Typical onset: 80,000-130,000 mi

Symptoms: Loss of boost pressure and power, Loud whistling or grinding noise from engine bay, Blue or black smoke from exhaust, Check engine light with boost control codes, Oil consumption increases dramatically

Fix: Turbos fail from oil starvation (often related to the piston ring oil consumption issue), bearing wear, or wastegate actuator problems. Replacement requires removing engine undertray and various exhaust components. 12-16 hours per turbo. Critical to address root cause (oil consumption) or replacement turbos will fail too. Many opt for both turbos at once given labor overlap.

Estimated cost: $4,500-7,000 per turbo, $8,000-12,000 for both

Typical onset: 60,000-100,000 mi

Symptoms: Hard starting or extended cranking, Rough idle and misfires, Loss of power under load, Check engine light with fuel pressure/trim codes, Fuel smell in engine bay

Fix: Direct injection systems are sensitive to fuel quality. High-pressure pump failures run 6-8 hours labor ($2,000-3,000 total). Injector failures less common but expensive—$600-800 each plus 1.5-2 hours per injector. Carbon buildup on intake valves (no port injection to clean them) causes rough running; walnut blasting service runs $600-1,000 (6-8 hours).

Estimated cost: $800-3,000 depending on component