"RX7 93-95 (13B REW twin turbo) loads of fun, but the REW was a weaker engine maintenance wise — it demands respect and attention."
RISKY
38/ 100
"Icon engine, punishing if neglected"
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Max HP
—
Torque Nm
5,000
Oil interval km
1
Recalls
7
Known issues
Known Issues
Apex Seal Failure€3,000-8,000 · 60,000-150,000 kmCRITICAL
Apex seals are the rotary engine's equivalent of piston rings. They are a known wear point on the 13B-REW and the leading cause of engine failure. Failure results in catastrophic loss of compression and typically requires a full engine rebuild. High heat, poor lubrication, and carbon buildup accelerate wear significantly.
Hard or failed cold starts
Severe loss of power
Excessive white or blue smoke from exhaust
Very low or uneven compression readings
Engine misfires at idle or low RPM
DIY: Expert
Sequential Twin Turbo System Failure€800-3,500 · 80,000-160,000 kmHIGH
The 13B-REW uses a sequential twin-turbo system (Hitachi turbos) — a small primary turbo for low RPM and a large secondary turbo that comes online at higher RPM. The system involves multiple solenoids, vacuum lines, actuators, and check valves. Any failure in the control system causes boost irregularities, hesitation, or complete secondary turbo drop-out. Age and heat degradation of vacuum lines is very common.
Flat spot or hesitation around 4,500–5,000 RPM
Secondary turbo fails to spool
Boost gauge anomalies
Boost pressure codes or check engine light
DIY: Advanced
Flooding and Cold-Start Carbon Buildup€200-1,500 · 0-80,000 kmHIGH
The rotary engine relies on fuel washing the rotor housing for lubrication and cooling. Short trips and city driving cause heavy carbon buildup and flooding, which prevents the engine from starting and accelerates apex seal wear. The engine must be regularly taken to operating temperature and revved to clear carbon.
Engine cranks but will not start, especially when cold
Fouled spark plugs
Rough idle with excessive fuel smell
Catalytic converter damage from unburnt fuel
DIY: Moderate
Coolant and Oil Seal Degradation (Rotor Housing Seals)€2,500-6,000 · 100,000-180,000 kmHIGH
The side seals and O-ring seals between rotor housings can degrade over time, allowing coolant or oil to enter the combustion chamber. This is often confused with apex seal failure but is a distinct failure mode requiring a full engine strip to diagnose and repair.
Persistent white smoke even after warm-up
Coolant loss without visible external leak
Oil consumption beyond normal rotary levels
Overheating events
DIY: Expert
Ignition Coil and Spark Plug Wear€150-500 · 30,000-80,000 kmMODERATE
The 13B-REW uses two spark plugs per rotor (leading and trailing), totalling four plugs. Ignition coils and plugs are under extreme thermal stress and wear faster than in a piston engine. Weak coils or worn plugs mimic apex seal failure symptoms and are frequently misdiagnosed. One Reddit post specifically notes an RX-8 (same rotary platform) bought for €800 due to apparent apex seal failure that turned out to be bad ignition coils.
Rotary engines consume oil by design as part of the apex seal lubrication process (metered oil injection). This, combined with potential flooding events, accelerates catalytic converter degradation. A clogged cat creates excessive backpressure that significantly reduces power and can cause overheating.
Progressive loss of high-RPM power
Overheating under load
Strong sulphur smell from exhaust
Elevated exhaust gas temperatures
DIY: Moderate
EGR Valve Issues€150-500 · 80,000-150,000 kmLOW
The EGR system on the 13B-REW is prone to carbon fouling and valve sticking, consistent with forum references to EGR fittings and related vacuum line degradation. A malfunctioning EGR can affect idle quality and emissions compliance.
Rough idle
Failed emissions test
Hesitation under light throttle
DIY: Moderate
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Buying Checklist
Perform a cold compression test on both rotors — minimum 8.0 bar (120 psi) per rotor with less than 10% variance; walk away if readings are low or uneven
Verify sequential turbo operation: drive the car through the full RPM range and confirm the secondary turbo engages cleanly around 4,500–5,000 RPM without hesitation or flat spots
Inspect all vacuum lines in the engine bay for cracking, hardening, or collapsing — replacement of the full harness is a common and necessary cost
Remove and inspect all four spark plugs for heavy carbon fouling or fuel saturation, which indicates flooding history or ignition system neglect
Check service history specifically for oil change intervals — rotary engines need oil changes every 5,000 km maximum; any record of extended intervals is a serious red flag
Inspect the coolant reservoir and oil filler cap for signs of contamination (milky oil or oily coolant), which indicates internal seal failure requiring an immediate engine rebuild
Service Reality
Community oil interval5,000 km
Oil specificationHigh-quality 10W-40 or 5W-30 semi-synthetic or full-synthetic. Must use an oil compatible with rotary engines — avoid energy-conserving oils with friction modifiers (API SN Resource Conserving or similar) as these harm apex seals. Pre-mix or metered injection oil must also be topped up regularly.
Est. ownership cost (2yr)€1,500–4,000 per year including consumables, ignition components, vacuum line replacements, and a rebuild reserve fund. A full engine rebuild when required costs €3,000–8,000 depending on specification.
The 13B-REW is one of the most extraordinary production engines ever built, but it is fundamentally a specialist's engine that rewards knowledge and punishes neglect. Any used example must be treated as a project car unless full documented maintenance history — including frequent oil changes and regular high-RPM operation — can be verified. Budget for an engine rebuild from day one, as virtually all surviving examples are approaching or have exceeded the apex seal wear threshold. This is not a car to buy cheaply and drive cheaply; it is a car to buy knowingly and maintain obsessively.
Parts People Buy
13B-REW Apex Seal Set (Cryogenically Treated)Link unavailable
Mazda RX-7 FD3S Ignition Coil SetLink unavailable
Mazda RX-7 Spark Plugs Leading Trailing SetLink unavailable