Mercedes-Benz GLA 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.
GLA 45 AMG — SUV Rocket
265 kW in the compact SUV — the weight costs a little sharpness compared to the A 45, but the GLA 45 is still a very serious fun machine.
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
On GLA X156 build years 2016–2018 the eCall emergency system could malfunction when Mercedes me services were active in transport mode. Automatic and manual emergency calls were not transmitted correctly. Fixed via OTA software update.
MOT reports cite brake lines and parking brake as typical weak points on the GLA X156. Brake lines are prone to corrosion.
The 7G-DCT in the GLA X156 shows jerky gear changes from 2nd to 3rd gear in heavy city use from approx. 60,000 km. Worn clutch plates (under 1.8 mm) are a common cause; a gearbox oil change can ease symptoms.
In cold weather the electric door mirrors on the GLA X156 often fail to fold in. The optional sunroof does not fully open or close at low temperatures. Cause is cold sensitivity of the drive motors and control units.
At motorway speeds above 120 km/h distinct wind noise is reported in the area of the door seals and bonnet. The bonnet vibrates measurably, indicating insufficient body sealing.
Many GLA X156 owners report annoying wind noise at higher speeds from around 120 km/h. The bonnet also vibrates at higher speed.
Owners report creaking and rattling noises from the interior. Seat belt guides and seats rattle frequently. Typical at higher mileages.
Reports & Tests
1 owner complaints filed with NHTSA (2013–2020). Most reported: Lane Departure (1).