What is the 2015-2023 Mercedes-Benz GLA Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654)?

GLA diesels (GLA 200d/220d), popular in Germany and the EU, develop clogged EGR valves and diesel particulate filters from soot buildup, plus AdBlue/SCR (NOx reduction) faults. EGR carbon fouling causes rough idle, reduced power and emissions faults; DPF blockage triggers limp mo… Repairs typically run $300-$2,500. Severity: high.

What is the 2015-2020 Mercedes-Benz GLA M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle)?

The GLA's M270/M274 turbo four-cylinder petrol engines are widely documented to suffer timing chain elongation and tensioner/guide wear, usually presenting between roughly 40,000-80,000 mi. A loose chain produces a distinctive rattle for the first few seconds after a cold start u… Repairs typically run $1,200-$3,000. Severity: high.

What is the 2015-2020 Mercedes-Benz GLA Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00?

The M270 uses a two-stage variable-displacement oil pump whose output is switched by a PWM solenoid (Y130) mounted inside the oil pan, with its wiring harness routed through the pan and out an oil-tight connector. The solenoid winding fails open, or the in-pan harness insulation… Repairs typically run $700-$2,200. Severity: high.

What is the 2015-2020 Mercedes-Benz GLA 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure?

The X156 GLA's 7G-DCT 7-speed wet dual-clutch transmission (type 724.0) is prone to low-speed shudder/judder, jerky or delayed engagement, and clutch slip, typically emerging from ~40,000-75,000 mi (60,000-120,000 km). Root causes are wet multi-plate clutch wear, degraded/contami… Repairs typically run $250-$3,200. Severity: high.

What is the 2015-2020 Mercedes-Benz GLA Turbo Coolant Line Leak?

The turbo coolant lines on the M270 engine develop leaks at the quick-connect fittings, causing coolant loss and potential overheating. The plastic connectors become brittle from heat cycling and crack. Repairs typically run $150-$600. Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA Transfer Case Noise (AWD Models)?

The 4MATIC transfer case on the GLA develops a whining or humming noise at highway speeds. The noise is caused by gear wear inside the power take-off unit that distributes torque to the rear axle. More common on vehicles that have seen off-road use or aggressive driving. Repairs typically run $200-$2,000. Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA MBUX/COMAND Infotainment Black Screen & Reboot (NHTSA Recall 21V354)?

GLA infotainment units suffer black/frozen screens and spontaneous reboots. On H247 cars this is the NVIDIA-Tegra-based MBUX head unit, which can fail to boot or reboot ~50 seconds after startup, disabling the rearview camera image (the basis of NHTSA recall 21V354 covering 2019-… Repairs typically run $0-$1,500. Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA M270/M274 Crankcase Ventilation (PCV) Diaphragm Rupture in Valve Cover - P052E?

The positive crankcase ventilation regulator is integrated into the plastic valve cover / breather assembly on the M270 and M274 2.0T engines (and carries over in modified form on the M260). The rubber diaphragm inside the partial-load crankcase ventilation valve hardens and tear… Repairs typically run $150-$2,000. Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA 12V Battery Parasitic Drain / No-Start After Sitting?

Mercedes communications directly support discharged 12V starter batteries and no-start conditions on both GLA generations. Communications 10157073, 10157076, 10158199 and 10158370 cover discharged batteries, no-start complaints and excessive quiescent current on earlier GLA vehic… Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA Rear Differential Carrier Whine/Clunk on 4MATIC Models?

On 4MATIC GLA250/GLA220d cars the rear differential carrier assembly is a documented weak point, producing whine, growl, or clunk from the rear (especially on/off throttle and cornering), often at surprisingly low mileage (~50,000-70,000 mi). The differential uses a very small fl… Repairs typically run $150-$2,500. Severity: medium.

What is the 2015-2020 Mercedes-Benz GLA Panoramic Sunroof Spontaneous Shattering / Front Roof Panel Detachment Recall?

GLA owners report the panoramic glass roof spontaneously cracking or shattering, the subject of class-action litigation against Mercedes over allegedly weak/stress-prone panoramic glass. Separately, Mercedes recalled certain 2014-2020 GLA (and other) vehicles because the fixed fr… Repairs typically run $0-$1,500. Severity: medium.

What is the 2015-2023 Mercedes-Benz GLA Blocked Panoramic Roof Drain Tubes Causing Water Ingress and Wet Carpets?

The GLA's panoramic roof drains water through four small tubes that run down the A- and C-pillars. Pollen, grit and - in documented GLA cases - a broken plastic bracket from the sunroof track itself block the tube or the drain channel, so water backs up over the channel lip and r… Repairs typically run $120-$1,500. Severity: medium.

What is the 2015-2024 Mercedes-Benz GLA Rear-View Camera Shutter/Flap Motor Failure Behind Trunk Handle?

The GLA hides its reversing camera behind a motorized flap in the tailgate handle trim, which is supposed to swing open when reverse is selected and close again to keep the lens clean. The small flap motor, its position sensor, and especially the flex wiring running into the movi… Repairs typically run $150-$900. Severity: low.

Mercedes-Benz · Known Issues

2018 Mercedes-Benz GLA Problems: 16 Known Issues

2018 model year · 2,400+ owner reports · Updated September 2026

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According to Au7o's analysis of 2,400+ owner reports, the 2018 Mercedes-Benz GLA has 16 documented known issues, with 7 rated critical. The most serious are Water Pump Failure ($400-$1,200 repair), GLA45 AMG M133 Turbo Wastegate Rod/Flapper Wear Causing Underboost and Limp Mode ($800-$6,000 repair), Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654) ($300-$2,500 repair), M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle) ($1,200-$3,000 repair), Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00 ($700-$2,200 repair), Steering Shaft Universal Joint Bearing Separation / 'Power Steering Malfunction' Warning ($0-$2,500 repair) and 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure ($250-$3,200 repair). The most commonly reported issue is Turbo Coolant Line Leak with 1,100 owner reports.

Frequently Asked Questions

What are the most common Mercedes-Benz GLA problems?

According to Au7o's analysis of 2,400+ owner reports, the 2018 Mercedes-Benz GLA has 16 documented issues. The most frequently reported are: Water Pump Failure, GLA45 AMG M133 Turbo Wastegate Rod/Flapper Wear Causing Underboost and Limp Mode, Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654). Of these, 7 are rated critical and should be addressed promptly.

Is the Mercedes-Benz GLA reliable?

The 2018 Mercedes-Benz GLA has 16 known issues documented across 2,400+ owner reports. 7 issues are rated critical: Water Pump Failure and GLA45 AMG M133 Turbo Wastegate Rod/Flapper Wear Causing Underboost and Limp Mode and Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654) and M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle) and Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00 and Steering Shaft Universal Joint Bearing Separation / 'Power Steering Malfunction' Warning and 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Mercedes-Benz GLA problems?

Repair costs for known Mercedes-Benz GLA issues range from $0 to $6,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Water Pump Failure, typically costs $400-$1,200 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2015-2020 Mercedes-Benz GLA Water Pump Failure?

The electric water pump on the M270 engine fails, causing loss of coolant circulation and rapid overheating. The pump motor or impeller breaks, and failure is often sudden with no warning. Common between 50,000-90,000 miles. Repairs typically run $400-$1,200. Severity: high.

All 16 Known Issues

Other Mercedes-Benz Models

Frequently Asked Questions

What are the most common Mercedes-Benz GLA problems?

Is the Mercedes-Benz GLA reliable?

How much does it cost to fix common Mercedes-Benz GLA problems?

What is the 2015-2020 Mercedes-Benz GLA Water Pump Failure?

What is the 2015-2019 Mercedes-Benz GLA GLA45 AMG M133 Turbo Wastegate Rod/Flapper Wear Causing Underboost and Limp Mode?

When Issues Typically Appear

2015-2019 Mercedes-Benz GLA: GLA45 AMG M133 Turbo Wastegate Rod/Flapper Wear Causing Underboost and Limp Mode#

2015-2020 Mercedes-Benz GLA: M270/M274 Timing Chain Stretch & Tensioner Wear (Cold-Start Rattle)#

2015-2020 Mercedes-Benz GLA: Variable Oil Pump Control Solenoid (Y130) Failure Inside Oil Pan - P06DA00#

2015-2023 Mercedes-Benz GLA: M270/M274 Crankcase Ventilation (PCV) Diaphragm Rupture in Valve Cover - P052E#

2015-2020 Mercedes-Benz GLA: Water Pump Failure#

2015-2020 Mercedes-Benz GLA: Turbo Coolant Line Leak#

2015-2023 Mercedes-Benz GLA: Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654)#

2015-2020 Mercedes-Benz GLA: Steering Shaft Universal Joint Bearing Separation / 'Power Steering Malfunction' Warning#

2015-2020 Mercedes-Benz GLA: 7G-DCT (724.0) Dual-Clutch Transmission Shudder & Mechatronics Failure#

2015-2023 Mercedes-Benz GLA: MBUX/COMAND Infotainment Black Screen & Reboot (NHTSA Recall 21V354)#

2015-2023 Mercedes-Benz GLA: 12V Battery Parasitic Drain / No-Start After Sitting#

2015-2024 Mercedes-Benz GLA: Rear-View Camera Shutter/Flap Motor Failure Behind Trunk Handle#

2015-2023 Mercedes-Benz GLA: Transfer Case Noise (AWD Models)#

2015-2023 Mercedes-Benz GLA: Rear Differential Carrier Whine/Clunk on 4MATIC Models#

2015-2020 Mercedes-Benz GLA: Panoramic Sunroof Spontaneous Shattering / Front Roof Panel Detachment Recall#

2015-2023 Mercedes-Benz GLA: Blocked Panoramic Roof Drain Tubes Causing Water Ingress and Wet Carpets#