2004 Mazda RX-8 Problems

RepairPal has identified the most common problems with the 2004 Mazda RX-8 as reported by actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.

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Known Problems

If the climate control's heat/cold knob is not adjusting to the desired temperature, a new climate control unit may be needed.

Mazda has issued Bulletin No. 01-010/10 for the above issue:

Some vehicles may experience the coolant level warning light comes on even though the correct amount of coolant is in the coolant reserve tank and radiator. The coolant level sensor float in the coolant reserve tank (A) is deteriorated and absorbs coolant. The float gets heavy, and sinks, causing the the coolant level warning light comes on. As a mass-production change, the design of the float has been modified.

Replace the necessary parts according to this VIN range.

• For VINs JM1FE****** 100000 to 157837 (built before July 1, 2005), replace the tank with sensor.

• For VINs JM1FE****** 157838 to 403405 (built on or after July 1, 2005), replace the tank only.

Hesitation and/or a lack of power can be caused by the secondary shutter valve (SSV) in the intake manifold becoming stuck open due to carbon build up around the SSV shaft. This may occur with no Check Engine light illumination but eventually the light will illuminate with code P2070 (Secondary Shutter Valve [SSV] stuck open). The cleaning procedure described under the service bulletin is a long process and it is recommended to install the updated SSV actuator and gaskets. The SSV is activated at higher RPM and the carbon accumulation can happen when it opens infrequently. The effects RX-8's built before April 18, 2007.

Some models may have a problem where the Check Engine light illuminates indicating an improperly tightened fuel cap. Due to improperly manufactured threads on the fuel filler pipe, the filler pipe may need to be replaced.

Be sure to check your owner's manual and use the correct engine oil. Mazda does not recommend using synthetic oil in the RX-8's rotary engine.