Below Average Reliability

2018 Mercedes-Benz GLS Pre-Purchase Inspection Checklist

X166 (1st Generation) · 3.0L Diesel V6 (GLS350d, 255hp) / 4.7L Biturbo V8 (GLS550, 449hp) / 5.5L Biturbo V8 (GLS63 AMG, 577hp) · $33,000 - $70,000

Known Issues — 2018 Mercedes-Benz GLS

CRITICAL

AIRMATIC air suspension compressor failure

CRITICAL

Air spring leaks causing uneven ride height

CRITICAL

7G-Tronic transmission conductor plate faults

MODERATE

Transfer case oil seal leaks

MODERATE

GLS63 M157 oil leaks from cam covers and front cover

MODERATE

Third-row seat power fold motor failure

What to Inspect

  • Check all four air suspension corners for height consistency
  • Verify third-row seat power fold motor operates correctly
  • Scan transmission for conductor plate error codes
  • Inspect GLS63 engine for oil seeps under hood
  • Check transfer case for oil leaks
  • Pull complete multi-module fault scan

Expected Maintenance Costs

ServiceIntervalCost
Service A (oil & filter)every 10,000 miles$350-$500
Service B (full inspection)every 20,000 miles$750-$1,100
Air spring replacement (each)as needed$1,000-$1,800
Transmission conductor plateas needed$1,000-$1,800
Brake pads and rotors (front)every 25,000-35,000 miles$900-$1,400
Third-row seat power fold motoras needed$500-$1,000

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