Mercedes CLA Common Faults (C117 & C118): What Goes Wrong on the Four-Door Coupe

CLA: A-Class mechanicals in a sleeker body

The CLA C117 (2013–2019) and C118 (2019–present) share their platform and engines with the A-Class, so many A-Class faults apply here too. However, the CLA's unique rear suspension and lower roofline introduce some specific issues. Overall reliability is average for the segment — neither outstanding nor terrible.

1. M270/M282 timing chain (petrol)

Same issue as the A-Class: the timing chain can stretch, particularly on cars that have missed oil changes or used the wrong oil specification. Cold-start rattle is the warning sign. Replacement: £1,400–£2,000 because of the transverse engine layout. Check camshaft adaptation values on Xentry at services above 60,000 miles.

2. DCT clutch wear (CLA 45 AMG and high-mileage standard cars)

The dual-clutch transmission in the CLA can suffer clutch pack wear, particularly on AMG models where the clutch handles more torque. Symptoms include judder during low-speed manoeuvres and delayed gear changes. A clutch pack replacement costs £1,200–£2,000. Regular gearbox fluid changes (every 40,000 miles) are the best prevention.

3. Rear axle bearing wear

The CLA's rear suspension design places significant load on the rear wheel bearings. Premature bearing wear causes a humming noise from the rear that increases with speed. Replacement: £250–£400 per side. This fault is more common on cars that regularly carry rear passengers or heavy loads.

4. Shock absorber mount corrosion

The upper rear shock absorber mounts can corrode, particularly on C117 cars. A corroded mount causes a knocking noise from the rear over bumps and is an MOT fail if severe. Replacement: £200–£350 per side including the mount and labour.

Ride quality: the CLA's Achilles heel

The CLA was designed as a style-first four-door coupe, and its suspension tuning reflects that priority. The rear suspension on non-AMG models uses a torsion beam rather than the multi-link setup found on the C-Class, and the dampers are tuned for handling rather than comfort. On London's potholed roads, the CLA rides noticeably firmer than an equivalent C-Class — this is not a fault, it is a design characteristic. However, the firmer suspension increases the loads on several components: rear shock absorber mounts wear faster (listen for knocking over bumps), the rear axle bushings degrade sooner, and the rear wheel bearings are more highly stressed. If you are considering a CLA for London driving, test-drive it on urban roads — not just smooth dual carriageways — to ensure you are comfortable with the ride quality. Many CLA owners coming from a C-Class or E-Class are surprised by how firm the ride is.

Interior quality: common wear points

The CLA's interior was designed to a price point below the C-Class, and several interior components show wear earlier than on larger Mercedes. The most common wear points are: the steering wheel leather on high-mileage cars (the CLA's steering wheel leather is thinner than on the C-Class and shows wear by 80,000 miles), the driver's seat bolster (the pronounced side bolster is prone to cracking and colour loss from entry/exit friction), and the silver trim on the dashboard and door cards (the painted plastic trim can chip and peel, revealing black plastic underneath). These are cosmetic issues rather than mechanical faults, but they affect the car's perceived quality and resale value. When viewing a used CLA, pay attention to the interior condition — a car with a worn interior has likely had a harder life, regardless of what the service history says.

The CLA Shooting Brake: additional considerations

The CLA Shooting Brake (estate) version shares all the mechanical components of the saloon but adds a powered tailgate that can develop faults with the latch mechanism or the gas struts. The tailgate struts are under higher load than on a C-Class estate because the CLA's sloping roofline means the struts must lift a heavier, longer tailgate at a less advantageous angle. A failing strut will not hold the tailgate open — particularly in cold weather — and replacement costs £150–£300 for the pair. The rear wiper motor is also more exposed to road spray than on upright estates and can fail from water ingress (£100–£200).