2006 MERCEDES-BENZ S500 W220

Typical onset: 80,000-150,000 mi

Symptoms: Rattling or ticking noise from lower engine on cold start that may disappear when warm, Metallic grinding sound from timing cover area, Sudden catastrophic failure with metal shavings throughout oil system, Check engine light with cam/crank correlation codes before total failure

Fix: Balance shaft gear (plastic composite) disintegrates, sending debris through oil galleries and destroying bearings, cam, crank. Requires complete engine tear-down or replacement. Short block replacement: 25-35 hours labor. Full rebuild with machine work: 35-45 hours. Many opt for used engine swap (15-20 hours) due to cost.

Estimated cost: $8,000-15,000

Typical onset: 70,000-120,000 mi

Symptoms: Harsh or delayed shifts, especially 2-3 and 3-4, Transmission slipping under load, Milky or contaminated transmission fluid, Limp mode with transmission fault codes, Coolant in transmission pan or transmission fluid in coolant

Fix: External or internal trans cooler fails, allowing coolant/ATF mixing. Contamination destroys valve body, conductor plate, and clutch packs. Requires cooler replacement, full flush, valve body replacement, and often conductor plate (13-pin connector). If caught early: cooler and flush only (6-8 hours). If delayed: valve body adds 4-6 hours, full rebuild 18-25 hours.

Estimated cost: $1,500-6,500

Typical onset: 60,000-100,000 mi

Symptoms: Vehicle sagging at one or more corners, especially after sitting overnight, Compressor running constantly or cycling frequently, Suspension warning light with 'Visit Workshop' message, Harsh ride quality or excessive body roll, Hissing sound from air struts when parked

Fix: Airmatic struts develop leaks at rubber bellows or air spring crimps. Compressor wears out from overwork due to leaks. Single strut replacement: 2-3 hours each. Compressor with relay: 3-4 hours. Most shops recommend replacing struts in pairs (front or rear). OE parts required for reliability.

Estimated cost: $1,200-3,500

Typical onset: 70,000-110,000 mi

Symptoms: Clunk or thud when shifting from Park to Drive or Reverse, Excessive vibration at idle, especially with AC on, Visible engine movement when revving in Park, Steering wheel shake at idle that smooths out at speed

Fix: Hydraulic mounts fail internally, losing fluid and damping. All five mounts (two engine, three transmission) should be replaced together for best results. Engine mounts: 2-3 hours each. Transmission mounts: 3-4 hours for rear, 2 hours each for sides. Access is tight; subframe may need partial drop.

Estimated cost: $1,800-3,200

Typical onset: 60,000-130,000 mi

Symptoms: No-start or extended cranking, especially when hot, Intermittent stalling at idle or while driving, Rough idle with P0340/P0345 cam sensor codes, Check engine light with cam/crank correlation faults, Loss of power and stumbling under acceleration

Fix: Crank sensor fails due to heat exposure behind starter. Cam adjusters (VVT solenoids) clog or fail electrically. Crank sensor: 1.5-2 hours (starter removal required). Cam adjusters: 2-3 hours each bank, valve covers must come off. Use OE sensors only; aftermarket have high failure rates.

Estimated cost: $400-1,200

Typical onset: 80,000-140,000 mi

Symptoms: ABC warning light with 'Stop Vehicle Too Low' message, Green fluid leaking under vehicle (ABC fluid), Vehicle sitting low with stiff, jarring ride, Whining or grinding from ABC pump at front of engine, Loss of active suspension function

Fix: ABC system uses high-pressure hydraulics prone to line, strut, and pump failures. Pump replacement: 6-8 hours. Strut replacement: 4-5 hours each. Lines/hoses: 2-4 hours depending on location. System requires specialized pressure flush after repairs. This system is exclusive to certain W220 models; confirm if equipped.

Estimated cost: $2,500-7,000

Typical onset: 50,000-90,000 mi

Symptoms: Coolant smell in cabin or under hood, Small coolant leak at rear of engine near firewall, Overheating or fluctuating temperature gauge, Coolant loss without visible external leaks, Steam from engine bay after shutdown

Fix: Plastic thermostat housing cracks; aluminum crossover pipes corrode at seams. Both sit at rear of engine against firewall. Access requires intake manifold removal. Combined job: 6-8 hours. Replace both simultaneously with upgraded metal thermostat housing. Flush and bleed cooling system properly to avoid airlocks.

Estimated cost: $900-1,600