Generations
SE — Series 1
2003–2008
13B Renesis
SE3P — Series 2
2008–2012
13B-MSP Renesis
Top issues to watch for
The most serious Mazda Rx 8 problems ranked by severity. We track 11 known issues — here are the ones you need to know about first.
Dangerous
Apex seal failure
The apex seals are triangular metal strips that seal the tips of the rotary engine's rotor against the housing wall, performing the same function as piston rings in a conventional engine. On the 13B Renesis engine, these seals wear prematurely due to inadequate lubrication and high operating temperatures, causing loss of compression and eventual engine failure. This is the most common catastrophic failure mode on RX-8s, with rebuild costs often exceeding the car's value. The Renesis design eliminated oil injection into the combustion chambers for emissions compliance, reducing apex seal lubrication compared to earlier rotary engines.
What happens if ignoredComplete apex seal failure renders the engine inoperable and requires a full rebuild costing £6,000-£12,000 or replacement with a remanufactured unit costing £4,000-£8,000. The car should not be driven once apex seal wear becomes severe as further damage to the housing will increase rebuild costs dramatically.
Specialist
£6,000–£12,000
Main dealer
£8,000–£15,000
Parts only
£2,000–£5,000
Dangerous
Suspension component corrosion and failure
The RX-8 suffers from widespread suspension component deterioration at rates far exceeding the national fleet average. MOT data shows suspension failures at 124.8 times the fleet average, with components becoming corroded, damaged, or insecurely attached. The aluminium front subframe and steel suspension arms are particularly affected, with bushings, ball joints, and mounting points failing prematurely due to design and material choices.
What happens if ignoredFailed suspension components create a direct safety risk through loss of vehicle control, particularly during emergency manoeuvres. Subframe corrosion can lead to complete structural failure. Component replacement costs vary widely depending on which items have failed, but comprehensive suspension refurbishment can cost £2,000-£4,000.
Independent garage
£200–£800
Specialist
£300–£1,000
Main dealer
£500–£1,500
Parts only
£150–£600
Major
Power steering fluid leak
The RX-8 power steering system fails at 123.7 times the fleet average, primarily due to leaks in the hydraulic system. The power steering pump, high-pressure lines, and steering rack seals are particularly prone to failure, causing loss of steering assistance and potential safety implications.
What happens if ignoredComplete power steering failure makes the car difficult to control at low speeds and during parking. Continued driving with leaking fluid can damage the pump beyond repair. Steering rack replacement costs £800-£1,500 plus labour.
Independent garage
£200–£600
Specialist
£300–£800
Main dealer
£500–£1,200
Parts only
£150–£500
Major
Emissions system failure
The RX-8 shows exceptionally high emissions failure rates, with levels exceeding limits at This is primarily due to the rotary engine's inherent design challenges with emissions control, catalytic converter degradation from apex seal wear, and secondary air injection system failures. The Renesis engine was specifically designed to meet emissions standards but remains problematic in this area.
What happens if ignoredEmissions failures prevent MOT certification and legal road use. Catalytic converter replacement costs £500-£1,500 per unit, and RX-8s have multiple cats. Secondary air injection system repairs add £300-£800. Continued driving with emissions failures may damage expensive components.
Independent garage
£300–£800
Specialist
£400–£1,000
Main dealer
£600–£1,500
Parts only
£200–£600
7 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 Rx 8 fails at a significantly higher rate than the average car.
Suspension ball joints worn
Suspension · 80-100k miles
MOT failure rate: 125x the fleet average
Sample: 1,414 tests
Power steering fault
Steering · 40-60k miles
MOT failure rate: 124x the fleet average
Sample: 2,669 tests
Coil springs broken
Brakes · 40-60k miles
MOT failure rate: 107x the fleet average
Sample: 3,512 tests
Emissions failure
Exhaust & Emissions · 60-80k miles
MOT failure rate: 78x the fleet average
Sample: 5,802 tests
Anti-roll bar links worn
Suspension · 40-60k miles
MOT failure rate: 56x the fleet average
Sample: 4,305 tests
Subframe bushes or mounts worn
Suspension · 20-40k miles
MOT failure rate: 27x the fleet average
Sample: 1,117 tests
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Related
Mazda Rx 8 reliability FAQs
What are the most common problems with the Mazda Rx 8?
The Mazda Rx 8 has 11 known issues across 3 severity levels. The most serious are: Apex seal failure, Suspension component corrosion and failure.
Is the Mazda Rx 8 reliable?
The Mazda Rx 8 has 2 dangerous and 7 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 Rx 8 problems?
Costs vary by issue. Independent garages are typically 30-50% cheaper than main dealers for most repairs.
Which Mazda Rx 8 generation is most reliable?
The SE (2003–2008) has the fewest dangerous issues (2). However, condition and service history matter more than generation — a well-maintained earlier car can be more reliable than a neglected newer one.