An iconic sports car powered by the unique Renesis rotary engine. The RX-8 is celebrated for its balanced handling, rear-wheel drive character, and 9,000 RPM redline. However, rotary engines demand specialized care that most owners underestimate. Apex seal wear is inevitable - around 50% of RX-8s have needed engine rebuilds before 160,000 km. High oil consumption (0.3-0.6L per 1,000 km) is by design, not a defect. The ignition system is notoriously weak and requires replacement every 50,000 km. Catalytic converters fail frequently from unburnt fuel. 2009+ Series 2 models have improved oiling (6 injectors vs 4) and higher oil pressure, making them more reliable. This is an enthusiast's car - only buy if you understand rotary maintenance or budget for specialist care.
Expected Annual Maintenance Costs
€2,200 - €4,400/year
15,000 km/year
Fixed costs
€1,100-1,800
Risk buffer
€1,100-2,600
What Can Break
bars = likelihood
Apex seal failure / low compression€3,000 - €6,500
The apex seals are the weakest link - most engines need rebuilding by 100,000-160,000 km · more· less
Apex seals are thin metal strips at the tips of the triangular rotors that maintain compression as the rotor spins. These seals gradually wear, and around 50% of RX-8s have required at least one engine replacement in their lifetime. Symptoms include hard cold starting, inability to restart when hot (within 3-5 minutes of shutdown), rough idle, loss of power, and blue smoke. Healthy compression should be 7.5-8.5 kg/cm² per face - below 6.5 kg/cm² indicates seal wear. Causes include insufficient lubrication, carbon buildup (especially in automatics), heat stress, and short-trip driving. A proper rebuild costs €3,000-4,500 using quality parts at an independent specialist, or €5,000-6,500 at a dealer. Prevention: maintain oil levels religiously, replace ignition components on schedule, warm engine fully before shutdown, use 2-stroke premix (120-150ml per tank), and drive spiritedly to operating temperature regularly.
Ignition coil/spark plug failure€400 - €600
Mazda used weak coils that fail every 30,000-50,000 km - this is preventive maintenance, not optional · more· less
The RX-8 uses underpowered ignition coils that overheat and lose spark strength progressively. Most specialists recommend replacing all 4 coils plus plugs and wires every 30,000 km maximum as preventive maintenance. A stock RX-8 with worn 50,000 km ignition lost 13.5% power (172 vs 199 whp) on the dyno. Weak ignition causes misfires, unburnt fuel entering the catalytic converter (destroying it), carbon buildup, and eventually apex seal damage. Cost for all 4 OEM coils, 4 spark plugs, and wires is approximately €400-600 at an independent shop. Symptoms include rough idle, hesitation, misfires, check engine light, and poor fuel economy. This is the single most important preventive maintenance item on the RX-8 - ignoring it will cascade into catalytic converter failure and engine damage.
Weak ignition and oil burning cause catalytic converter failure, leading to overheating and engine damage · more· less
Rotary engines inject oil into the combustion chamber by design, and when combined with weak ignition coils, massive amounts of unburnt fuel and oil enter the exhaust. This coats and eventually destroys the catalytic converter. A clogged cat creates back pressure that overheats the engine, causes heat soak back to the apex seals (damaging them), and reduces power dramatically. Symptoms include engine stalling, inability to rev past 4,000-5,000 RPM, check engine light, glowing orange/red catalytic converter, and a rotten egg smell. The 2009+ Series 2 received a redesigned cat to address this. OEM replacement costs €1,500-2,200; aftermarket cats fail quickly on RX-8s due to heat - only high-quality units like Magnaflow or stock Mazda parts last. Some owners opt for a high-flow cat or decat pipe (€600-900) where legal. Prevention: replace ignition system on schedule.
Starter motor failure (cold weather)€300 - €700
Weak starter can't spin engine fast enough in cold weather, leading to flooding and no-start conditions · more· less
Mazda used an inadequate starter motor on 2004-2006 RX-8s. There was a recall in 2006 and starters were upgraded, but older vehicles remain problematic. In cold weather, the weak starter can't crank the engine fast enough to build compression for ignition. If the engine doesn't start within 7-8 seconds of cranking, it floods with fuel. Symptoms include slow cranking, clicking sounds, intermittent no-start (especially cold mornings), and engine flooding requiring the de-flood procedure (hold accelerator to floor and crank for 7-8 seconds). 2009+ Series 2 models received a new, more powerful starter and larger battery (80 Ah vs 50-75 Ah). Replacement cost is €300-500 for the starter plus €100-200 labor. Prevention: keep battery healthy, clean starter motor connections, and always warm the engine fully before shutdown to avoid flooding.
Engine flooding€0 - €150
Shutting off the engine before it reaches operating temperature causes flooding and no-start · more· less
Rotary engines run very rich during cold start to ensure smooth operation. If you shut the engine off before it reaches operating temperature (cold start cycle incomplete), unburnt fuel sits on the rotor face near the spark plugs, flooding the engine. This is especially common when moving the car short distances (parking, garage). A flooded engine won't start and requires the de-flood procedure: depress accelerator fully to floor, crank for 7-8 seconds to clear fuel, then release and start normally. Never attempt multiple 1-2 second start attempts - this worsens flooding. If DIY de-flood fails, a shop will need to remove spark plugs and manually clear the chambers (€100-150). Repeated flooding damages the weak starter motor and catalytic converter. Prevention: ALWAYS warm the engine to operating temperature before shutdown - let it idle for 3-5 minutes if needed. Never move the car "just a few meters" when cold.
Carbon buildup in rotor housings€35 - €4,000
Gentle driving, short trips, and poor ignition cause carbon deposits that jam apex seals · more· less
The Renesis engine struggles to expel carbon compared to earlier rotaries. Oil injection and rich running create carbon deposits on rotor housings, in seal grooves, and on side seals. Excessive buildup jams apex seals and side seals, causing compression loss - this is especially common in automatics. Symptoms include rough idle, loss of power, and eventually complete seal failure. Prevention: drive the car hard regularly (Italian tune-up) - take it to redline once warmed up, use 2-stroke premix (helps create softer carbon), avoid only short trips, keep ignition system fresh, and use high-quality fuel. Treatment: Mazda Zoom-Zoom engine cleaner decarb procedure (€35 DIY or €150-250 at shop) can help as a last resort before rebuild. Some owners use Seafoam or steam cleaning. If carbon has already jammed seals and compression is low, only an engine rebuild (€3,000-4,000) will fix it. Premixing with JASO-FD 2-stroke oil (120-150ml per tank) significantly helps prevent buildup.
Water pump/thermostat failure€600 - €1,200
Electric water pump integrated with thermostat typically fails between 110,000-160,000 km · more· less
The RX-8 uses an electric water pump integrated with the thermostat housing - a common failure point between 110,000-160,000 km. When it fails, the engine overheats rapidly, potentially warping the rotor housings and causing catastrophic damage. Symptoms include coolant warning light, temperature gauge climbing toward hot, engine overheating, or poor cabin heating. The integrated design means you must replace the entire assembly (€400-500 for the part) plus 4-6 hours labor due to poor accessibility. Total cost is €600-900 at an independent shop or €1,000-1,200 at a dealer. 2009+ Series 2 received an improved cooling system with new radiator, fan motors, and 3-speed fan control (vs 2-speed). Prevention: monitor coolant level, watch temperature gauge, and replace coolant on schedule (every 3 years). Never ignore overheating - shut down immediately to prevent engine damage.
Front control arm cracks (2004 models)€400 - €800
2004 models had a recall for cracked front control arms - check if completed · more· less
Early 2004 RX-8s suffered from cracked front lower control arms due to a manufacturing defect. There was an official recall to replace them. Symptoms include clunking from front suspension, wandering steering, uneven tire wear, and in severe cases, visible cracks in the aluminum control arm. If buying a 2004 model, verify the recall was completed. Replacement cost (if not covered by recall): €400-600 for both sides including labor at an independent shop. The OEM RX-8 control arms have excellent internal bushing design - aftermarket polyurethane bushings actually reduce ride quality. Stick with OEM Mazda replacement parts. Later models (2005+) don't have this issue. Control arm ball joints and bushings on all years wear gradually - expect replacement around 160,000 km under normal conditions.
Door lock actuator/window motor failure€150 - €400
Door lock motors fail, causing continuous clicking and battery drain; window motor gears strip · more· less
The RX-8's door lock actuators are prone to failure, particularly the driver's door. Symptoms include doors not locking/unlocking with key/remote/interior switch, continuous clicking noise (draining battery), and complete lock failure. The actuator motor gets stuck in a cycle. Replacement cost is €20-40 for a Mazda 6 actuator (same part), available on Amazon, plus 1-2 hours labor (€100-150). Window motors also fail - the plastic gears strip their teeth, causing slow or non-functional windows. While in the door, it's recommended to replace both actuator and window motor gears preventively. DIY-capable owners can do this for €50-80 in parts. Check the power window disable switch first - accidentally bumping it mimics motor failure. Total professional repair for one door: €150-250 labor plus parts.
Power steering (EPS) module failure€120 - €1,600
Electric power steering module fails intermittently or completely, causing heavy steering · more· less
The RX-8 uses electric power steering (EPS) rather than hydraulic. The control module can fail due to internal component wear or moisture intrusion. Symptoms include intermittent power steering loss, heavy steering at low speeds, groaning/whining sounds when turning, and B1342 EPS fault code. The system also disables when battery voltage is low. One known issue: a short coolant drain hose allows vapor to condense on the EPS connector when hot, causing shutdown. Dealer quotes run €1,400-1,600 for module replacement, but the part can be found online for €120-300 and installed by a competent mechanic. If only the connector is corroded, cleaning may solve it (€50-100 diagnosis). Check battery voltage and alternator output first - low voltage mimics EPS failure. If the module truly failed, replacement is the only fix (not repairable).
Clutch wear (manual transmission)€800 - €1,500
Clutch life varies widely based on driving style - typically 80,000-150,000 km · more· less
Manual transmission RX-8s use a conventional clutch that wears based on driving style. Enthusiastic drivers and track use shorten life to 80,000-100,000 km; gentle highway use can reach 150,000+ km. Symptoms include slipping (RPM rises without speed increase), high engagement point, difficulty shifting, and burning smell. The 2009+ Series 2 received a new 6-speed manual from the MX-5, with reverse relocated next to 1st gear (vs next to 6th on Series 1). Clutch kit (disc, pressure plate, throwout bearing) costs €300-600 for quality parts. Labor is 4-6 hours due to transmission removal, totaling €500-900. Complete job: €800-1,200 at independent shop or €1,200-1,500 at dealer. Flywheel resurfacing adds €100-150. The rotary's smooth power delivery is easy on clutches compared to high-torque engines. Manual gearbox is significantly more reliable than the automatic.
Alternator failure€400 - €650
Alternator brushes, bearings, or voltage regulator fail - typical lifespan 150,000-200,000 km · more· less
The alternator can fail due to worn brushes, bad bearings, or voltage regulator issues. Symptoms include battery/alternator warning light, dead or frequently depleted battery, grinding/whining noise, flickering lights, and voltage below 13.8V or above 14.8V when running. Test with a multimeter at the battery terminals with engine running - should read 13.8-14.4V. Check the 120-amp fusible link in the engine bay fuse box first - if blown, no charging occurs. Also inspect battery terminals for corrosion (common cause of apparent charging issues). The 2009+ Series 2 received a new alternator design. Replacement cost: €200-350 for alternator, 2-3 hours labor (€200-300), totaling €400-500 independent or €550-650 dealer. If only brushes or regulator failed, some shops rebuild for €250-350. Ensure all battery cable connections are clean and tight before replacing alternator.
High-maintenance car requiring specialist knowledge
The RX-8 demands rotary-specific care that most generic mechanics lack. Apex seal wear and ignition system weakness are inherent design characteristics, not isolated defects. Budget for an engine rebuild between 100,000-160,000 km - it's not "if" but "when." Only buy this car if you're willing to learn rotary maintenance, use a rotary specialist, or have the budget for higher costs. Series 2 (2009+) models are noticeably more reliable due to improved oiling and cooling. The car rewards proper care but punishes neglect harshly.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete records essential, especially oil changes every 5,000 km and ignition system replacements. Look for rotary specialist stamps, not generic shops.
Tires
Stock size 225/45R18. Check tread depth, age (date codes), and uneven wear. RX-8 is rear-biased so rears wear faster.
Cold start test
CRITICAL: Engine must be completely cold (sit overnight). Hard cold starting indicates apex seal wear. Should start within 3-5 seconds of cranking when cold.
Hot restart test
After 20+ minute test drive, shut off engine. Wait 3-5 minutes, then restart. If engine won't restart when hot, apex seals are worn.
Test drive
Minimum 30 minutes including varied speeds. Rev to 7,000-9,000 RPM in 2nd/3rd gear (safe location) to verify power. Loss of power = compression issues.
Specific for this vehicle
Compression test (MANDATORY)
A rotary compression test is non-negotiable. Must test all 6 faces (3 per rotor) at 250 RPM. Healthy: 7.5-8.5 kg/cm². Minimum acceptable: 6.5 kg/cm². All faces within 1.0 of each other. Below 6.5 or large variance = worn apex seals = walk away or negotiate €3,000-4,500 off for rebuild. Insist seller provides recent compression test or pay €100-150 for specialist to test before purchase.
Oil consumption verification
Ask owner how much oil they add between changes. Correct answer: 0.3-0.6L per 1,000 km (approximately 1L per tank). If they say "none" or look confused, they've been neglecting oil - engine damage likely. Check dipstick - oil should be full and clean.
Ignition system service history
When were coils, plugs, and wires last replaced? Should be every 30,000-50,000 km maximum. If "never" or unknown = budget €400-600 immediately. Weak ignition destroys catalytic converter and engine.
Catalytic converter inspection
After 20-minute drive, check for rotten egg smell or glowing orange/red cat (visible underneath). Rev engine to 4,000-5,000 RPM - should respond smoothly. If it bogs down or won't rev, cat is clogged (€1,500-2,500 replacement).
Check for engine flooding history
Ask owner if car has ever flooded. Frequent flooding indicates starter weakness and/or low compression. Try cold start yourself - should start immediately without extended cranking.
Verify 2-stroke premix usage
Ask if owner premixes 2-stroke oil into fuel (120-150ml per tank). If yes = good sign of informed ownership. If no = increased wear likely. Check for Idemitsu/Motul 2T oil bottle in trunk.
Inspect exhaust smoke
Some blue smoke on startup is normal (oil injection by design). Excessive smoke throughout drive or black smoke indicates problems - rich running or seal wear.
Check coolant system
Coolant level should be full and clean (not brown/oily). Look for leaks around water pump (front of engine). Check expansion tank cap for oil contamination. Series 2 (2009+) has 3-speed fan - listen for fan operation at temperature.
Control arms and bushings (2004 models)
If buying 2004 model, verify front control arm recall completed. Jack up front - grab wheel at 3 and 9 o'clock and push/pull. Excessive play = worn ball joints or bushings.
Door locks and windows
Test all door locks with key, remote, and interior switches. Listen for continuous clicking (failed actuator draining battery). Test all windows - should move smoothly without hesitation.
Power steering operation
Turn steering lock-to-lock at idle. Should be light with no groaning, clicking, or resistance. EPS warning light = module failure (€120-1,600).
Series 1 vs Series 2 identification
2009+ Series 2 have improved oiling (6 injectors), higher oil pressure, new catalytic converter, improved cooling, and stronger chassis. Strongly prefer Series 2 for better reliability. Check VIN or look for Series 2 badging.
Recalls and Technical Service Bulletins
Front control arm cracks (2004 models)Verify completed
Starter motor replacement (2004-2006)Check if updated
195 Technical Service Bulletins issuedReview at RX8Club.com
The RX-8 has 195 documented TSBs, one of the highest counts for any Mazda. Check recall completion using VIN at vinrcl.safercar.gov or mazdarecallinfo.com. TSBs are not recalls - they document known issues and solutions but aren't required to be fixed free of charge. Review TSBs for your specific year at RX8Club.com or mazdaproblems.com before purchase.
Warranty Status
Factory warranty (3 years/100,000 km)Expired on all RX-8s
Emissions/catalyst warranty (8 years/130,000 km)Expired on most units
Extended warranty availabilityLimited - most providers exclude rotary
All RX-8s (2003-2012) are well outside factory warranty. Many extended warranty providers specifically exclude rotary engines or have severe limitations on coverage. Some specialist insurers offer rotary-specific coverage but with high premiums and low claim limits. Budget for repairs out-of-pocket. The catalytic converter may still be covered under emissions warranty if within 8 years/130,000 km - check with Mazda dealer using VIN.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified rotary engine specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.