Credov's researched list of the 7 faults the Mercedes-Benz A-Class W177 is known for (2019–2020), 7 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: Sniff under the bonnet for petrol at idle and after the drive, and look for wet or chafed fuel hoses.
Why it matters: Leaking fuel in a hot engine bay is a fire risk; a petrol smell is a stop-and-fix item, not something to drive home on.
What to look for: Check for any steering warning in the cluster, and feel for steering going suddenly heavy at low speed or when parking.
Why it matters: Sudden loss of power steering makes the car much harder to turn, especially at low speed, which is a crash risk.
What to look for: Let the engine auto-stop at lights several times and check it restarts promptly every time, noting any power loss on the drive.
Why it matters: An engine that will not restart in traffic, or cuts out on the move, leaves the car stranded where it could be hit.
Sources: 1
What to look for: On a long drive with the A/C on, watch that the temperature gauge holds steady and does not swing or climb.
Why it matters: A mechanic diagnosed this as a known common fault on one affected car, and driving on a failing thermostat risks lasting engine damage.
What to look for: Press the carpet in both front footwells and beside the centre tunnel for dampness, and watch for airbag or engine warnings.
Why it matters: Water around the airbag and other control units causes expensive electrical faults that keep coming back until the source is fixed.
What to look for: Sniff for burning oil after the drive, and look around the turbo and under the engine for fresh oil.
Why it matters: Oil dripping onto a hot turbo or exhaust can start a fire, and a car that keeps losing oil can damage its engine.
Sources: 1
What to look for: Feel for a misfire or rough idle once warm, and read the scan for misfire codes and their history.
Why it matters: The fix is a new cylinder head, which is a major repair if the car is not covered.
Sources: 1
Got a question about a Mercedes-Benz A-Class W177? 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.