Credov's researched list of the 3 faults the Mercedes-Benz GLS 350d is known for (2012–2019), 3 of them serious or costly. Each one says what to look for when you check the car, so you can spot it before you buy. Not every car has these faults: they are the ones worth checking on this model.
What to look for: With a torch, look down the back of the engine and at the gearbox bellhousing for wet, dusty oil.
Why it matters: The seals themselves are cheap, but the job means stripping the top of the engine, making it a big labour bill, and oil can run down onto the belt tensioner and starter if it is left unchecked.
What to look for: Check the dash for any AdBlue, emissions or 'starts remaining' message, and check for a blue filler cap.
Why it matters: The car shows an AdBlue or emissions warning and then counts down a number of starts or km until it will not restart at all; because the heater is built into the tank or pump assembly, the repair is expensive.
What to look for: If possible see the car after it has stood overnight, and listen for hissing or a long-running compressor.
Why it matters: A leak overworks the compressor until it overheats and fails; the car sits low or lopsided after parking and may show an Airmatic warning before the compressor itself gives out.
Got a question about a Mercedes-Benz GLS 350d? Ask Credov: a noise, a warning light, a part or how to fix it.
On top of the faults above, every Credov inspection covers the basics: fuel smell, leaks or filler rust, engine oil leaks, power steering fluid leak, drive belt cracks or squeal, rust underneath: chassis and mounts, engine mounts, engine oil level and colour, coolant level, colour and leaks, head gasket failure signs, cold start: rattle, knock or smoke, rough or hunting idle, engine running hot on gauge, gearbox or diff oil leak, swapped gearbox without lvv and more.
Researched by Credov from manufacturer recalls and service bulletins, owner reports and workshop sources. Repair prices are typical ranges, not quotes. See also fault codes and repair costs.