Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2004 Mazda RX-8 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2004 Mazda RX-8. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to pull to the shoulder of the roadway, where the vehicle failed to restart. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the engine. The dealer determined that the engine had no compression. The vehicle was repaired, but the failure reoccurred. The manufacturer was notified of the failure but provided no assistance. The failure mileage was 60,000.
Engine naturally wears out especially after 200k miles due to friction in the natural design of the Rotary engine, resulting in losing its overall function such as turning off in the middle of a drive due to loss of compression from worn Apex Seals of the Rotary. The rotary engine requires a replacement of the Apex Seals to continue functioning normally to avoid any unpredictable accidents due to engine failure. An event occurred where my RX-8 went into limp mode in the middle of the freeway as i was commuting due a misfire from poor compression, this is more then likely a common event nowadays for RX-8 owners starting at the S1 2004 models with newer models soon to follow the same incident as me. This is completely unsafe especially traveling at 65 MPH
Tl* the contact owns a 2004 Mazda RX-8. While driving through a drive-thru window, the vehicle stalled. The vehicle was pushed to a parking space. While attempting to start the vehicle, a loud pop sound emerged from the engine compartment. Immediately afterwards, smoke and flames appeared. The fire department extinguished the flames. A police report was filed. The vehicle was not evaluated by the insurance company. The manufacturer was not notified of the failure. The vehicle was not taken to a dealer for diagnostic testing. The approximate failure mileage was 150,000.
Tl* the contact owns a 2004 Mazda RX-8. The contact took the vehicle to the local dealer (modern Mazda Dodge Ram, 68 waterbury rd, thomaston, ct, 06787, [phone]) to be serviced per NHTSA campaign numbers: 17V355000 (suspension), 16V793000 (fuel system), and 17V354000 (fuel system). The contact was informed that the recall repairs would take one day to complete; however, it took four days. The contact retrieved the vehicle and, while the accelerator pedal was depressed, the vehicle failed to accelerate and the check engine indicator illuminated. The contact took the vehicle back to the dealer and was informed that they would repair the failure. One week later, the dealer stated that the contact could retrieve the vehicle, but then diagnosed that the compressor failed and it would only last approximately two more years. The dealer stated that the engine needed to be replaced. …
The 2004 rx8 has internal seals fail prematurely. This causes the engine to "blow" by a loss of compression in one of the two rotor chambers. The problem being the car with still run with half power. I continued to drive to find help off the highway. The rotor that is not working is dumping gas into the catalytic converter. By the time I parked, I could smell burning fiber and plastic and the exhaust shot out several large chunks of red hot ceramic material. The catalytic converter was bright orange and the entire underside of my car is melted. Looking on internet under "2004 RX 8 engine failure" I have seen several other stories with similar results but worse. Is it possible that the fuel tank could explode with such heat so near if you continued to drive. This happens anywhere from 12,000 miles to 100,000 miles and beyond. …
Tl contact owns a 2004 Mazda RX-8. The contact stated that the ignition cylinder on the vehicle malfunctioned. The engine warning light illuminated while driving approximately 55 MPH and the vehicle stalled. An excessive amount of smoke was also bellowing from underneath the vehicle. The dealer stated that raw gas was being dumped into the catalytic converter which caused a fire to occur in the wiring harness. The vehicle was towed to the dealer and who stated that the wiring harness and the ignition cylinder needed to be replaced at the owners expense. The dealer called the Mazda district representative to discuss the failure and they stated that there was nothing they could do. The vehicle was not repaired. Mazda filed case number 130341420 regarding the failure. The failure and current mileages were 43,358.
Tl* the contact owns a 2004 Mazda RX-8. While driving at various speeds, the contact noticed strong exhaust fumes in the vehicle. In addition, while making a left turn at a low speed, the contact heard a loud noise underneath the vehicle. In addition, the contact stated that the vehicle failed to remain in position. The contact had to continuously maneuver the steering wheel in order to make the vehicle remain in position. The vehicle was taken to an independent mechanic who was unable to diagnose or repair the vehicle. The vehicle was then taken to a dealer, but was not diagnosed or repaired. The vehicle was previously repaired under NHTSA campaign numbers: 05V325000 (suspension) and 05V317000 (engine and engine cooling). The manufacturer was notified of the failure. The failure mileage was 82,000.
Tl contact owns a 2004 Mazda rx8. The contact noticed a failure with the engine on four different occasions. The vehicle lost power and would not accelerate properly. She also noticed a burnt, rubbery smell coming from the passenger console. She took the vehicle to the dealer three times and they stated that she needed a new motor. The dealer replaced the first motor in July of 2008 during her third visit. The contact noted that the dealer would attempt to repair the issue, but she was never able to drive home successfully without a failure occurring. She was recently informed that a second new motor would be needed. The vehicle has not yet been repaired. The manufacturer has not been notified. The current mileage was approximately 59,000 and failure mileage was approximately 50,000.
Tl contact owns a 2004 Mazda RX-8. He stated the vehicle hesitated to start and that while driving it failed to operate at minimal speed. He also stated the vehicle would not accelerate properly. The check engine warning light illuminated and he noticed smoke coming from under the hood and the middle interior console. An independent mechanic stated that the catalytic converter needed to be replaced. The manufacturer stated that there was a previous campaign pertaining to the same failures; however, the repairs were made with the original owner. The contact is responsible for paying the repair cost. The contact stated the part was reprogrammed but not replaced as relayed to him by the manufacturer. No repairs had been made. The failure and current mileages were under 101,000.
Engine light came on with no noticeable problems. Called dealer who advised bringing it in. On way to dealership, approx. 4 miles, car began to misfire, producing smoke from exhaust pipes. By the time I pulled into the dealership, smoke was coming from every area of underside of car, as well as interior. Wife following said flames were coming from both exhaust pipes. Car only has 37,000 miles, and all dealer servicing were done since purchase of vehicle. After 2 weeks of contact with home office, Mazda has agreed to pay for repairs of exhaust system, but I am liable for physical damage to car which includes melted carpeting, spark plugs, etc. Was told both coils were the cause of problem.
Related recalls
Engine and engine cooling
If certain passenger vehicles are parked and the engine is operated at high RPM's for an excessive length of time, some of the parts around the exhaust system can melt and produce a variety of malfunctions.
Remedy: Dealers will inspect and replace parts. The recall began on August 30, 2005. Owners May contact Mazda at 1-800-222-5500.
Engine complaints in other RX-8 years
Frequently asked questions
How common are engine problems on the 2004 Mazda RX-8?
NHTSA has 139 complaints about the engine & cooling of the 2004 Mazda RX-8, 28% of the model year's 490 complaints. The component named most often is engine (37 mentions).
Is there a recall for 2004 Mazda RX-8 engine problems?
Yes — NHTSA recall 05V-317 (engine and engine cooling, Jul 7, 2005). Recall repairs are free at authorized dealers.
At what mileage do 2004 Mazda RX-8 engine problems start?
Half of the complaints with a recorded mileage happened before about 55,000 miles, and 22% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 9 fires and 2 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.