2020 Mercedes-Benz GLA Problems: 3 Issues Every Owner Should Know

2020 Mercedes-Benz GLA Problems: 3 Issues Every Owner Should Know | Au7o

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When Issues Typically Appear

Turbo Coolant Line Leak

30K-70K

Transfer Case Noise (AWD Models)

40K-90K

Water Pump Failure

50K-90K

025K50K75K100K mi

Community Reported

800 owners

On the 2015-2020 Mercedes-Benz GLA 2.0L M270 Turbo, 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.

This issue also affects: Audi A4 allroad, Audi A8, Audi Q7

Common Symptoms

Engine temperature spikes rapidly
No heat from cabin heater

How to Fix

Replace the electric water pump and thermostat together. Use OEM or Pierburg (OEM supplier) parts. Flush the cooling system with fresh Mercedes-approved coolant. Monitor the temperature gauge closely on high-mileage GLA models.

What Owners Are Using

Parts and tips from 800+ owners who fixed this issue

NoteIf the temperature gauge moves above the halfway mark, pull over immediately. The electric water pump gives zero warning before complete failure — overheating for even 2 minutes can warp the head.

Typical repair cost:$400 - $1,200

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800+ owners have reported this issue

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Community Reported

Medium Confidence800 reportsLast reported by owners Oct 2025Reviewed Mar 2026

Community Reported

1,100 owners

On the 2015-2020 Mercedes-Benz GLA, 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.

This issue also affects: Mercedes-Benz B-Class, Mercedes-Benz CLA

Common Symptoms

Low coolant warning light
Sweet coolant smell from engine bay

How to Fix

Replace the turbo coolant lines with updated parts featuring reinforced connectors. Top off coolant and bleed the system. Inspect the turbo oil lines at the same time as they share the same access area.

What Owners Are Using

Parts and tips from 1,100+ owners who fixed this issue

TipCheck coolant level monthly on the GLA250. The turbo line leak is slow and you may not notice puddles, but coolant level drops steadily over weeks.

Typical repair cost:$150 - $600

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1,100+ owners have reported this issue

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Community Reported

High Confidence1,100 reportsLast reported by owners Sep 2025Reviewed Mar 2026

Community Reported

500 owners

On the 2015-2023 Mercedes-Benz GLA, 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.

Common Symptoms

Whining noise at highway speed
Humming that changes with vehicle speed

How to Fix

Drain and refill the transfer case fluid first — old fluid can cause whining. If noise persists, the power take-off unit needs rebuilding or replacement. Use only Mercedes-approved transfer case fluid.

What Owners Are Using

Parts and tips from 500+ owners who fixed this issue

TipChange the transfer case fluid every 40,000 miles. Mercedes does not list this as a scheduled service item but it dramatically extends transfer case life.

Typical repair cost:$200 - $2,000

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500+ owners have reported this issue

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Community Reported

Medium Confidence500 reportsLast reported by owners Jun 2025Reviewed Mar 2026

Frequently Asked Questions

What are the most common Mercedes-Benz GLA problems?

According to Au7o's analysis of 2,400+ owner reports, the 2020-2020 Mercedes-Benz GLA has 3 documented issues. The most frequently reported are: Water Pump Failure, Turbo Coolant Line Leak, Transfer Case Noise (AWD Models). Of these, 1 is rated critical and should be addressed promptly.

Is the Mercedes-Benz GLA reliable?

The 2020-2020 Mercedes-Benz GLA has 3 known issues documented across 2,400+ owner reports. 1 issue is rated critical: Water Pump 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 $150 to $2,000, 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.

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.

2020 Mercedes-Benz GLA Problems: 3 Issues Every Owner Should Know

All 3 Known Issues

When Issues Typically Appear

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

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

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

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

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

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

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 2015-2020 Mercedes-Benz GLA Turbo Coolant Line Leak?

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