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Mercedes Benz X Class Problems & Known Issues

The most common Mercedes Benz X Class problems ranked by severity — what to watch for, what it costs to fix, and what happens if you ignore it.

Generations

W470 — X-Class
2017–2021
2.3 dCi, 3.0 V6 dCi

Top issues to watch for

The most serious Mercedes Benz X Class problems ranked by severity. We track 5 known issues — here are the ones you need to know about first.

Major
Electronic parking brake failure (W470)
W4702017–202120k–60k miles
The X-Class uses an electronic parking brake system that can fail on one side, creating an uneven braking force that affects parking brake efficiency. MOT data shows this model fails parking brake tests at over 24 times the national average, with both inoperative single-side failures and insufficient overall efficiency. The system relies on electric actuators at each rear brake caliper that can seize or lose power, requiring replacement of the actuator unit.
What happens if ignoredA failed parking brake actuator creates uneven braking forces and can cause the vehicle to roll on slopes. The affected side may not engage properly, leading to MOT failure and potential safety risk when parking on inclines. Replacement typically requires both actuators to be changed as a pair.
Independent garage
£400–£650
Specialist
£500–£800
Main dealer
£700–£1,100
Parts only
£250–£450
Major
Engine management light and emissions faults (W470)
W4702017–202120k–100k miles
This typically indicates emissions system faults including EGR valve problems, DPF sensor failures, or NOx sensor malfunctions. The shared Nissan/Renault diesel technology has known issues with carbon build-up in the intake system and DPF regeneration problems in urban driving conditions.
What happens if ignoredEmissions system faults typically require diagnostic work to identify the specific failed component, which may include EGR valve replacement, DPF regeneration or replacement, or NOx sensor replacement. Costs vary significantly depending on the root cause, from £300 for sensor replacement to £2,500 for DPF replacement.
Independent garage
£200–£1,800
Specialist
£250–£2,200
Main dealer
£350–£2,800
Parts only
£150–£2,000
Minor
Front suspension component wear (W470)
W4702017–202120k–120k miles
3L diesel variants. This is likely related to the vehicle's pickup truck architecture and higher unsprung weight compared to conventional passenger cars.
What happens if ignoredWorn suspension components affect handling and may cause uneven tyre wear. While not immediately dangerous, deteriorated bushes and worn joints will eventually cause MOT failure and should be addressed to maintain safe handling characteristics. Multiple components may need replacement simultaneously.
Independent garage
£150–£400
Specialist
£200–£500
Main dealer
£300–£700
Parts only
£80–£300
Minor
Brake disc premature wear (W470)
W4702017–202140k–120k miles
The X-Class shows higher than average brake disc wear rates, failing MOT tests for significantly worn brake discs at 2.9 times the fleet average. This is likely related to the vehicle's higher kerb weight compared to conventional passenger cars and the demands placed on the braking system in commercial use. Both front and rear discs can be affected, with the 3.0L V6 variants showing higher failure rates, possibly due to increased vehicle weight.
What happens if ignoredWorn brake discs will eventually fail the MOT test and affect braking performance. While not immediately dangerous at the point of MOT advisory, discs that are significantly worn should be replaced promptly. Replacement often involves both discs and pads simultaneously.
Independent garage
£200–£350
Specialist
£250–£400
Main dealer
£300–£500
Parts only
£120–£250

1 more known issues tracked

Including wear items, electrical niggles, and generation-specific problems. Check a specific car to see which issues apply to its age and mileage.

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Related

Mercedes Benz X Class reliability FAQs

What are the most common problems with the Mercedes Benz X Class?

The Mercedes Benz X Class has 5 known issues across 2 severity levels. The most common problems relate to Electronic parking brake failure (W470) and Engine management light and emissions faults (W470).

Is the Mercedes Benz X Class reliable?

The Mercedes Benz X Class has 0 dangerous and 2 major known issues. No dangerous issues are tracked, which is a positive sign.

How much does it cost to fix Mercedes Benz X Class problems?

Repair costs range widely. The most significant issue (Electronic parking brake failure (W470)) costs £400–£650 at an independent garage. Minor issues can be under £200. Always get a full inspection before buying.