Mercedes-Benz CLA 45 AMG
World record holder at launch: the M133 was the world's most powerful production four-cylinder in 2013. 2.0 litres, 360 hp, 1.8 bar boost — absurd on paper, surprisingly reliable in practice. The well-known weakness is oil contamination of the turbo oil supply line on early vehicles (before Feb. 2014), which led to a recall. The 7G-DCT dual-clutch overheats under hard use in stop-and-go traffic. Keep to service intervals and treat the gearbox gently and you get a long-lived high-performance engine.
Hot-Hatch in Coupé Clothing
Same engine, more attractive body: the CLA 45 looks a notch more grown-up with its coupé silhouette than the A45, but drives just as ferociously. All-wheel drive, 360 hp, and a front end that gives nothing away about what lies beneath. An ideal everyday sports car for those who want performance without drawing attention with a sporty look.
Engine Weaknesses 9
Recall campaign for vehicles built before Feb. 2014: contaminated oil feed line to the turbo causes bearing wear and turbo damage. 365 affected vehicles.
Symptoms: Power loss, oil mist from exhaust, whistling from turbocharger, in extreme cases engine failure
The 7G-DCT dual-clutch gearbox frequently shows judder when pulling away on the M133 AMG. The clutch wears prematurely due to high torque spikes. Repair costs €3,500–€6,000.
Symptoms: Judder when pulling away and during gear changes (especially cold), slipping clutch feel, gearbox enters limp mode
The M133 AMG shares the well-known Mercedes issue of leaking camshaft solenoids. Accelerated by higher engine temperatures in the AMG application.
Symptoms: Lambda sensor faults, rough idle, CEL. As it progresses, multiple electrical codes. Oil traces at camshaft solenoids
Recall for 365 vehicles built before Feb. 2014: residual contamination of the oil feed line could cause power loss or turbocharger damage. Only affects early production A45 and CLA45.
Under extreme use the turbocharger impeller can develop shaft play. In the worst case the wheel can detach and introduce foreign objects into the combustion chamber, causing engine damage.
Symptoms: Whistling or hissing noise, power loss, in extreme cases engine damage
The highly-tuned M133 tends towards elevated oil consumption through worn valve stem seals and PCV system, especially with spirited driving.
Symptoms: Dropping oil level between oil changes, occasional blue smoke on cold start or overrun
The M133 timing chain can stretch prematurely with regular high-rpm use and generate rattling noises. Critical when oil change intervals are exceeded.
Symptoms: Rattling on cold start, rough idle, sporadic hesitation under load
The high-pressure fuel pump of the M133 is marginally designed for 360–381 hp. Fault codes for too-high or too-low fuel pressure occur. Pump replacement €1,500–€4,000.
Symptoms: CEL, fuel pressure fault codes P0087/P1223, hesitant throttle response, misfires under load, occasional limp mode
The AMG Speedshift 7G-DCT overheats in frequent stop-and-go on motorway construction sites. Gearbox goes into limp mode. Mercedes acknowledged this as a design characteristic. Software update can reduce frequency.
Symptoms: Gearbox enters limp mode, jerky gear changes, warning message in instrument cluster
Vehicle Weaknesses 7
Multiple recall actions on the CLA C117 concerned cracked fuel lines in the engine bay as well as brake booster deficiencies and faulty airbag cable routing. Affected vehicles should be checked for open recalls at the KBA.
The 7-speed dual clutch gearbox in the CLA C117 tends toward juddering gear changes, especially when pulling away and in traffic. Clutch packs wear prematurely with intensive urban use. Software updates help temporarily; at high mileages a gearbox oil change is needed.
Defective cable guides on door locks cause central locking to fail. Moisture ingress into the footwell trim puts additional strain on the electrics.
Water enters the footwells through sealing defects, which can lead to electrical damage and corrosion. Vehicles with panoramic roof are particularly affected.
According to ADAC breakdown statistics, the starter battery is the most common breakdown cause on the CLA C117. The high quiescent current draw from numerous control units drains the battery quickly during short-distance use or extended standing.
Despite its premium positioning, the CLA C117 showed sub-optimal panel gaps at door trim panels and self-releasing trim strips. Owners report squeaking and rattling noises from the interior that worsen with vehicle age.
CLA C117 owners report comparatively early brake disc wear on the front axle. Brake pads and discs often due from 40,000–50,000 km. Sporty driving style and AMG Line models more severely affected.