2017 Mercedes-Benz GLS diesel: common problems and MOT failures

What goes wrong more than usual on a 2017 Mercedes-Benz GLS diesel?

Parts flagged at MOT more often on the 2017 Mercedes-Benz GLS diesel than on all cars registered in 2017.

• Drive shaft (CV) joints4.4× usual
  Mercedes-Benz GLS

  4.8% All 2017 cars

  1.1%

  Failed outright at MOT: 0.8%, against 0.6% of all 2017 cars. The rest were advisories or minor defects.

  Rough price £60–£350 our estimate

  At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

Common 2017 Mercedes-Benz GLS diesel MOT failures and advisories

The share of 2017 Mercedes-Benz GLS diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Tyres
  27% of testsRough price £70–£150

  At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

• Brakes
  13% of testsRough price £150–£350

  At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

• Driveshafts and joints
  5% of testsRough price £60–£350

  At the viewing: On full steering lock, drive slowly and listen for clicking from the front wheels.

• Wipers, windscreen and mirrors
  5% of testsRough price £15–£250

  At the viewing: Check for chips in the driver's view, and test the wipers and washers.

• Lights and electrics
  3% of testsRough price £10–£80

  At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

• Oil and fluid leaks
  2% of testsRough price £80–£600

  At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Questions to ask the seller before buying a 2017 Mercedes-Benz GLS diesel

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

1. Any recent work on the drive shaft (cv) joints? (Flagged at MOT 4.4× as often on the 2017 Mercedes-Benz GLS diesel as on other cars the same age.)
2. Can I see the service history and receipts for any big jobs?