2018 MERCEDES-BENZ S600

Typical onset: 40,000-80,000 mi

Symptoms: Metallic knocking from engine bay that worsens with RPM, Low oil pressure warning despite fresh oil, Metal shavings visible in oil during changes, Engine seizes suddenly if ignored

Fix: Complete engine-out teardown to replace bearings or full rebuild/replacement. This M279 V12 has documented issues with bearing material degradation and oil starvation. Expect 45-60 hours labor minimum for proper rebuild with machine work, or 25-30 hours for short block replacement if available.

Estimated cost: $28,000-55,000

Typical onset: 50,000-90,000 mi

Symptoms: Excessive oil consumption (1 quart per 500-800 miles), Blue smoke on startup or acceleration, Loss of power and misfires, Check engine light with misfire codes on multiple cylinders

Fix: Requires engine removal and complete teardown. Piston rings wear prematurely on this engine, often scoring cylinder walls beyond honing limits. Typically needs all 12 pistons, rings, and cylinder boring/sleeving. 50-70 hours labor depending on cylinder damage extent.

Estimated cost: $32,000-60,000

Typical onset: 60,000-100,000 mi

Symptoms: Rattling noise on cold start that disappears when warm, Limp mode activation under boost, Overboost or underboost fault codes, Whistling or hissing under acceleration

Fix: Both turbos typically need replacement together as they wear similarly. Wastegate actuators fail, but entire turbo assemblies are usually recommended. Engine-out service on V12 for proper access. 18-24 hours labor plus turbo units.

Estimated cost: $12,000-18,000

Typical onset: 70,000-120,000 mi

Symptoms: Coolant loss with no visible leaks, White smoke from exhaust, Overheating in one bank or both, Oil contamination in coolant or vice versa, Rough idle and misfires

Fix: V12 head gasket jobs require engine removal for proper access to rear cylinders. Both banks typically done simultaneously. Heads must be checked for warpage and cracks. 40-50 hours labor with machine shop work.

Estimated cost: $15,000-25,000

Typical onset: 50,000-90,000 mi

Symptoms: Transmission fluid spots on driveway, Low transmission fluid warning, Burnt transmission fluid smell, Harsh shifting when fluid gets low

Fix: Cooler lines corrode where they connect to the radiator and transmission. Lines must be replaced as assemblies. Access is challenging due to V12 packaging. 6-9 hours labor including proper flush and fill.

Estimated cost: $2,200-3,800

Symptoms: Hesitation or stumbling under hard acceleration, Intermittent stalling, especially when fuel level is low, Extended cranking before starting, Limp mode under load

Fix: V12 has multiple fuel pumps and filters in the tank module. Tank must be dropped for access. Contamination issues are common with these cars if premium fuel isn't consistently used. 5-7 hours labor including fuel system cleaning.

Estimated cost: $1,800-3,200

Typical onset: 60,000-100,000 mi

Symptoms: Clunk when shifting from park to drive or reverse, Excessive vibration at idle in gear, Visible sagging of transmission when inspected on lift

Fix: Hydraulic transmission mount deteriorates from heat and weight of the V12/trans combo. Replacement requires supporting transmission and subframe work. 3-5 hours labor.

Estimated cost: $1,200-2,000