Generations
GG — GG (2002-2008)
2002–2008
1.8 MZR, 2.0 MZR, 2.3 MZR, 2.0 MZR-CD
GH — GH (2008-2013)
2008–2013
1.8 MZR, 2.0 MZR, 2.3 MZR, 2.0 MZR-CD
GJ — Second Generation
2008–2018
2.0 Skyactiv-G, 2.5 MZR, 2.2 MZR-CD, 2.2 Skyactiv-D
Top issues to watch for
The most serious Mazda 6 problems ranked by severity. We track 6 known issues — here are the ones you need to know about first.
Dangerous
Subframe and suspension mounting point corrosion
The Mazda 6 suffers from severe corrosion around subframe mounting points and suspension component attachment areas. The steel subframe and surrounding chassis areas are inadequately protected from salt water ingress, leading to structural corrosion that compromises vehicle rigidity and suspension mounting integrity. This affects both generations but is particularly severe on 2002-2008 models. MOT data shows this model failing at up to 94.7 times the national average for suspension component corrosion and 58.4 times the average for mounting point corrosion. The issue worsens progressively and represents a genuine safety risk.
What happens if ignoredSevere corrosion can lead to suspension components detaching from the body shell, causing immediate loss of vehicle control and potentially fatal accidents. Even moderate corrosion represents an MOT failure and requires immediate welding repair. Repair costs typically range from £800-£2,500 depending on the extent of corrosion, but many cars become uneconomical to repair.
Independent garage
£800–£2,500
Specialist
£1,200–£3,000
Main dealer
£1,800–£4,000
Parts only
£200–£800
Major
DPF regeneration issues and blockage (GJ)
The diesel particulate filter (DPF) on 2.2-litre diesel Mazda 6 models suffers from frequent blockage issues, particularly when used for predominantly short urban journeys. The DPF requires regular high-temperature regeneration cycles to burn off accumulated soot particles, but insufficient motorway driving prevents this process. The SH-VPTS Skyactiv-D engine is particularly affected due to its advanced combustion system producing fine soot particles. Blocked DPF causes excessive smoke emission, reduced power, and eventual engine protection mode activation.
What happens if ignoredA completely blocked DPF will put the engine into limp mode, limiting power and speed. Professional DPF cleaning costs £300-£500, while DPF replacement costs £1,200-£2,000. Continued driving with a blocked DPF can damage the turbocharger and require engine internal cleaning.
Independent garage
£300–£800
Specialist
£400–£1,200
Main dealer
£500–£1,500
Parts only
£800–£1,200
Minor
Rear suspension bush deterioration
The rear suspension trailing arm bushes and lateral link bushes on the Mazda 6 deteriorate prematurely due to their rubber composition and exposure to road contaminants. This is separate from the structural corrosion issue but contributes to the high MOT failure rates for suspension components. Worn bushes cause imprecise rear axle location, leading to poor handling, tyre wear, and eventual MOT failure for excessive movement in suspension components.
What happens if ignoredWorn bushes cause progressive handling deterioration and uneven tyre wear. The car remains safe to drive but will eventually fail an MOT test. Full rear bush replacement typically costs £400-£800 depending on which bushes require replacement.
Independent garage
£300–£600
Specialist
£400–£800
Main dealer
£600–£1,200
Parts only
£150–£300
Minor
Parking brake cable corrosion and adjustment
The rear parking brake cables on the Mazda 6 are prone to corrosion and stretching, leading to poor handbrake efficiency that fails MOT requirements. The cables run under the car and are exposed to road salt and water, causing the inner cable to seize within the outer sheath. This affects all variants but is particularly common on cars used in areas with heavy winter salt use. MOT data shows this model failing at 27.3 times the national average for parking brake efficiency.
What happens if ignoredPoor handbrake efficiency causes an MOT failure and represents a safety risk when parking on slopes. Cable replacement typically costs £200-£400 for both sides. If left unaddressed, the cables can seize completely, requiring rear brake disc removal for replacement.
Independent garage
£180–£350
Specialist
£200–£400
Main dealer
£300–£500
Parts only
£80–£150
2 more known issues tracked
Including wear items, electrical niggles, and generation-specific problems.
MOT failure hotspots
Based on DVSA MOT test data. These are the items where the Mazda 6 fails at a significantly higher rate than the average car.
Anti-roll bar links worn
Suspension · 40-60k miles
MOT failure rate: 95x the fleet average
Sample: 1,699 tests
Headlight fault
Lights & Electrics · 20-40k miles
MOT failure rate: 76x the fleet average
Sample: 538 tests
Subframe bushes or mounts worn
Suspension · 0-20k miles
MOT failure rate: 56x the fleet average
Sample: 121 tests
Emissions failure
Exhaust & Emissions · 120-150k miles
MOT failure rate: 38x the fleet average
Sample: 8,415 tests
Suspension component damaged or corroded
Suspension · 20-40k miles
MOT failure rate: 36x the fleet average
Sample: 752 tests
Seat mounting fault
Seatbelts & Airbags · 20-40k miles
MOT failure rate: 32x the fleet average
Sample: 1,796 tests
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Related
Mazda 6 reliability FAQs
What are the most common problems with the Mazda 6?
The Mazda 6 has 6 known issues across 4 severity levels. The most serious are: Subframe and suspension mounting point corrosion.
Is the Mazda 6 reliable?
The Mazda 6 has 1 dangerous and 1 major known issues. Most can be avoided with a thorough pre-purchase check and full service history.
How much does it cost to fix Mazda 6 problems?
Repair costs range widely. The most significant issue (Subframe and suspension mounting point corrosion) costs £800–£2,500 at an independent garage. Minor issues can be under £200. Always get a full inspection before buying.
Which Mazda 6 generation is most reliable?
The GG (2002–2008) has the fewest dangerous issues (0). However, condition and service history matter more than generation — a well-maintained earlier car can be more reliable than a neglected newer one.