2004 Mazda RX-8

The 2004 Mazda RX-8 is a unique sports car known for its distinctive rotary engine and balanced handling. This model year marked the introduction of the RX-8 and was offered with a 1.3-liter RENESIS rotary engine in two power outputs: a higher-powered version producing around 238 horsepower and 159 lb-ft of torque (typically paired with the 6-speed manual transmission) and a lower-powered version producing around 197 horsepower and 164 lb-ft of torque (paired with the 4-speed automatic transmission). Drivers appreciate the RX-8 for its engaging driving experience and distinctive styling, but common complaints often revolve around the rotary engine’s reliability, high oil consumption, and potential for flooding.

Engine

1.3L RENESIS Rotary (High Power - 6-Speed Manual)

• Low Compression/Loss of Power
  • Description/Symptoms: Rotary engines are prone to losing compression over time due to wear on the apex seals. This manifests as difficulty starting, particularly when hot, reduced power, poor fuel economy, and eventually engine failure.
  • Solution: Compression test to diagnose. Engine rebuild or replacement is usually required.
  • Estimated Cost to Fix: $3,000 - $7,000+
  • Recalls: None Found
• Catalytic Converter Failure
  • Description/Symptoms: A failing catalytic converter often results from incomplete combustion due to a weakened or failing rotary engine. Symptoms include decreased performance, a rotten egg smell, and potentially a check engine light.
  • Solution: Replace the catalytic converter. Address the underlying engine issue (low compression) to prevent recurrence.
  • Estimated Cost to Fix: $800 - $2,000
  • Recalls: None Found
• Flooding
  • Description/Symptoms: Rotary engines are more susceptible to flooding than piston engines. This occurs when excessive fuel enters the engine and prevents it from starting.
  • Solution: Deflooding procedures often involve removing the fuel pump fuse or using the deflood procedure in the car’s ECU. Frequent short trips can exacerbate this issue.
  • Estimated Cost to Fix: Typically free, if you know how to do it, but can range from $100-$300 if you take it to a shop.
  • Recalls: None Found

1.3L RENESIS Rotary (Low Power - 4-Speed Automatic)

• Low Compression/Loss of Power
  • Description/Symptoms: Similar to the higher-powered version, the lower-powered rotary engine also suffers from apex seal wear and compression loss, leading to difficult starting, reduced power, and poor fuel economy.
  • Solution: Compression test to diagnose. Engine rebuild or replacement is usually required.
  • Estimated Cost to Fix: $3,000 - $7,000+
  • Recalls: None Found
• Catalytic Converter Failure
  • Description/Symptoms: Failing catalytic converter often results from incomplete combustion due to a weakened or failing rotary engine. Symptoms include decreased performance, a rotten egg smell, and potentially a check engine light.
  • Solution: Replace the catalytic converter. Address the underlying engine issue (low compression) to prevent recurrence.
  • Estimated Cost to Fix: $800 - $2,000
  • Recalls: None Found
• Flooding
  • Description/Symptoms: Rotary engines are more susceptible to flooding than piston engines. This occurs when excessive fuel enters the engine and prevents it from starting.
  • Solution: Deflooding procedures often involve removing the fuel pump fuse or using the deflood procedure in the car’s ECU. Frequent short trips can exacerbate this issue.
  • Estimated Cost to Fix: Typically free, if you know how to do it, but can range from $100-$300 if you take it to a shop.
  • Recalls: None Found

Transmission

6-Speed Manual

• Synchro Wear
  • Description/Symptoms: Grinding or difficulty shifting into certain gears, particularly 2nd or 3rd.
  • Solution: Transmission rebuild or replacement.
  • Estimated Cost to Fix: $2,000 - $4,000
  • Recalls: None Found

4-Speed Automatic

No Issues Found

Suspension

• Damper/Shock Absorber Failure
  • Description/Symptoms: Leaking fluid, bouncing, and reduced ride quality.
  • Solution: Replace the shocks and/or struts.
  • Estimated Cost to Fix: $400 - $1,200+ (depending on brand and labor)
  • Recalls: None Found
• Control Arm Bushing Wear
  • Description/Symptoms: Noisy suspension, clunking sounds, and imprecise handling.
  • Solution: Replace worn bushings or the entire control arm.
  • Estimated Cost to Fix: $200 - $800+
  • Recalls: None Found

Electrical

• Ignition Coil Failure
  • Description/Symptoms: Misfires, rough running, and check engine light. Rotary engines are sensitive to ignition system health.
  • Solution: Replace the ignition coils. It’s recommended to replace all coils at the same time.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found

Exterior

• Rust
  • Description/Symptoms: Rust formation on the body, especially in areas prone to moisture and road salt exposure (wheel wells, rocker panels).
  • Solution: Rust repair, body panel replacement, and rustproofing.
  • Estimated Cost to Fix: $500 - $5,000+ (depending on severity)
  • Recalls: None Found

Interior

• Sun Visor Sagging
  • Description/Symptoms: The sun visors gradually losing their ability to stay in the upright position.
  • Solution: Replace the sun visor.
  • Estimated Cost to Fix: $50-$150+
  • Recalls: None Found

Summary

The 2004 Mazda RX-8 presents a unique ownership experience but is plagued with reliability concerns, primarily centered around the RENESIS rotary engine. Compression loss, catalytic converter issues, and flooding are common and potentially expensive problems. Suspension and electrical components can also suffer from wear and tear. Repair costs can range from a few hundred dollars for minor issues to several thousand for major engine work. Addressing these issues proactively is crucial for maintaining the RX-8 and enjoying its performance.