2004–2011 Mazda RX-8: Hard start or no start, rough running (rotary flooding or low compression)
Likely causes, ranked
- Flooded engineDIY
- Worn apex seals (low compression)Shop
- Weak ignition coils or batteryDIY
Real-owner fix counts will appear here as reports come in.
DIY or shop: See DIY or shop section
Parts to check
As an Amazon Associate I earn from qualifying purchases.
These are search links; confirm fitment for your exact engine and trim. Affiliate disclosure
Symptom: Cranks but won't start (often after a short cold start and shutoff), rough idle, or poor power.
Likely causes
- Flooding. RX8Club owners use a de-flood procedure to clear fuel and recover.
- Low compression. Readings that stay low after de-flooding mean worn seals and a rebuild or replacement.
DIY or shop?
De-flooding is DIY. A rotary-specific compression test and rebuild are shop jobs.
Useful steps
- Don't shut it off right after a cold start.
- De-flood per the procedure.
- Get a rotary compression test.
Vehicle focus: 2004–2011 Mazda RX-8.
Safety / mechanic note
None
Recalls & service bulletins
No recalls or service bulletins are listed for this page yet.
NHTSA complaints: 68 keyword-matched complaints for Mazda RX-8 2004–2011 (of 815 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-15).
Always check your VIN for open recalls at nhtsa.gov/recalls.
Sources
What actually fixed it?
Had this problem? Tell other owners what the real fix was. Reports are counted above; we never show made-up numbers.