Mercedes-Benz Maybach GLS 600
The M177 is AMG's most widely used V8 biturbo today and is considered technically mature and long-lived. The hot-V turbocharger arrangement delivers spontaneous response with barely perceptible lag. Weaknesses are manageable: wastegate rattle in cold weather, ignition coil recall for early 2015 model years, valve cover gaskets with age. Regular oil changes with attention to oil quality deliver a very robust engine. In direct comparison with the M156 less emotional, but significantly more reliable and efficient.
Maybach with AMG V8 — maximum luxury, minimum noise
The GLS 600 is not an AMG and has no desire to be: 557 hp from the M177 propel the flagship with a gentleness unexpected at this power level. The air suspension filters everything away, the V8 rumbles far in the background. To hear the engine you need to open a window. For long-distance travel and prestige the best SUV in the Mercedes lineup — the AMG GLS 63 is louder, but not better.
Engine Weaknesses 8
The MCT Speedshift gearbox (wet launch clutch instead of torque converter) wears the clutch significantly faster in frequent stop-and-go. Clutch replacement requires gearbox removal.
Symptoms: Judder on pull-away, clutch slip at full load, gearbox warning message, delayed engagement from standstill
Identical issue to the M176/M278: the solenoid leaks, oil migrates by capillary action through the wiring harness. On AMG vehicles this is even more frequent due to higher oil temperatures.
Symptoms: Cold-start rattle, camshaft adjuster fault code, oil traces on connector, potential ECU consequential damage
The camshaft cover gaskets on the M177 AMG V8 become brittle from the high heat exposure in the hot-V. Oil escapes onto turbochargers and exhaust system.
Symptoms: Oil smell on hot engine, oil film on turbochargers, smoke from engine bay
The M177 has several electric auxiliary coolant pumps for charge air cooling. These fail and lead to elevated charge air temperatures with power reduction.
Symptoms: Power reduction during spirited driving, cooling system fault codes, elevated charge air temperature
The camshaft adjuster solenoids on the M177 can leak internally or stick. Fault codes for camshaft position and rough running are the result.
Symptoms: Check engine light, rough idle, camshaft position fault codes, power loss in the lower rev range
Vehicles with M177/M178 engines built between Jan. and Nov. 2015 had faulty ignition coils that caused misfires. Mercedes replaced affected parts under a recall.
Symptoms: Rough idle, misfires, check engine light, occasional limp mode
The wastegate flaps of the BiTurbo system clatter briefly after cold start. Normally disappears after a few seconds. With prolonged operation replace the wastegate actuator.
Symptoms: Metallic clattering directly after cold start, disappears after warm-up, permanent with wear
As a direct-injection engine without port injection, carbon residues build up on the intake valves. Walnut blasting every 50,000–80,000 km recommended. Performance loss is gradual.
Symptoms: Gradually roughening idle, slight power loss, elevated fuel consumption
Vehicle Weaknesses 6
The 48V earth connection under the passenger seat was fastened with insufficient torque. High currents raise junction temperature — fire risk. 52,363 vehicles affected.
During gentle braking with gear change 7→6 and simultaneous 48V recuperation, the engine can stall. 260,658 vehicles worldwide affected.
Incorrectly routed A/C condensate drain hoses allow water ingress into the interior. Contact with electrics causes short circuits. 171,463 vehicles affected.
Leaks in the air suspension system cause the GLS to sag. Air spring bellows, lines and compressor are the most common weak points.
MBUX shows crashes during extended operation (black screen). Total failures occur especially after long drives over 400 km. Software updates often only provide temporary relief.
The MBUX infotainment no longer responds to inputs or displays frozen content. After software updates, stability sometimes worsens.
Reports & Tests
1 owner complaints filed with NHTSA (2019–2025). Most reported: Latches & Locks (1).