2012–2025 Mercedes-Benz A-Class · common problems & known faults

7G-DCT dual-clutch jerkiness and clutch wear

Typically appears

70,000+ miles

What to inspect

Crawl in traffic and feel for shunting

Timing chain wear on older petrols and oil leaks

Typically appears

90,000+ miles

What to inspect

Cold-start listen and underside inspection

MBUX screen failures and reversing camera dropouts

Typically appears

Age-related

What to inspect

Test MBUX, voice control and camera

Front bushes and knocking over broken roads

Typically appears

70,000+ miles

What to inspect

Listen over speed bumps

Water ingress into the boot causing damp smells and potential rear SAM unit electrical issues.

Typically appears

40,000-80,000 miles

What to inspect

Lift the boot floor carpet and inspect the spare wheel well and tool tray for standing water, rust, or heavy condensation.

NOx sensor failure on diesel models triggering the EML and an AdBlue countdown restriction.

Typically appears

50,000-80,000 miles

What to inspect

Start the engine and cycle through the instrument cluster messages to check for an illuminated EML or an active AdBlue range restriction warning.

Fuel filler flap actuator seizes internally, preventing the flap from opening at the petrol station.

Typically appears

30,000-60,000 miles

What to inspect

Lock and unlock the car using the key fob, then press the fuel filler flap to ensure it springs open smoothly without needing the emergency release.

Clicking or plastic creaking noises from the steering column clock spring during low-speed manoeuvres.

Typically appears

30,000-70,000 miles

What to inspect

With the engine running and the car stationary, turn the steering wheel lock-to-lock and listen closely for a plastic clicking noise directly behind the airbag.