really awful
Typical Repair Cost:
Average Mileage:
98,850 miles
Total Complaints:
8 complaints

Most Common Solutions:

  1. replace engine (4 reports)
  2. buy another car (2 reports)
  3. not sure (2 reports)
2004 Mazda MAZDA6 engine problems

engine problem

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2004 Mazda MAZDA6 Owner Comments

problem #8

Apr 102015


  • Automatic transmission
  • 90,099 miles


I am a pensioner on a fixed income that does not allow for expensive fixes to a vehicle. This car was given to me by my daughter, who thought the problem was a simple head-gasket replacement. Turns out the motor is toast and the car is, without thousands of dollars invested to replace the engine, headed for the junkyard. With all the problems reported on this motor, Mazda should have stood behind it and recalled the engine. Since getting it home, I've researched on the web about the problems, and they're non-stop. One person in the area has two of them sitting in his yard and both have the same problem - engines fried. The price of the repairs are not even close to what the vehicles are worth. His advice was to just get rid of it - no sense putting in a rebuilt motor that might go at any time.

- Lyn T., N. Battleford, SK, Canada

problem #7

Aug 012013

MAZDA6 S 3.0L V6

  • Manual transmission
  • 114,000 miles

I financed the car November 2012. Car began making knocking noise around July 2013. I was driving to work one day and I began to hear odd noises from my engine. It sounded like it was squeaking or something but it began to get louder and louder to the point where my car just died. Engine was done. Could not afford to buy a replacement Mazda engine so I went with the Ford Fusion engine swap.

After a lot of research about this car I think the main issue is the whole exhaust system. From the headers to the pre-cats and cat itself. The whole set up is an engine murderer and I am looking to get rid of this car as soon as I can. Car is still running with the Ford Fusion engine but for God knows how much longer.

My advice for any car buyer? STAY AWAY FROM THIS CAR! IT LOOKS REALLY NICE WITH THE SPOILER AND SIDE SKIRTS BUT IT IS NOT WORTH IT!!!! UNLESS YOU BUY AFTERMARKET HEADERS AND KNOW WHAT YOU ARE DOING, THEN GO AHEAD. This engine issue is only one of the many things that have gone wrong with this car.

- Jorge M., Boston, MA - Massachusetts, USA

problem #6

Jan 132013


  • Manual transmission
  • 120,000 miles

Timing chain broke. $3700 to fix. Mostly all the money went to labor.

- Bonnie D., Columbus, OH, USA

problem #5

May 122014

MAZDA6 S 3.0L V6

  • Automatic transmission
  • 103,000 miles


I just bought My 2004 Mazda 6 s 3.0L V6 with 103,000 miles on it from a dealer in SC. I was aware of rough running engine when I bought it so trailored it home and to the mechanic shop. I was told that a mechanic had already checked it over and it needed a EGR, valve part was around $180 here. My mechanic on other hand said engine was ruined.

I found this website and saw a reported case really similar with car running really rough like out of time or misfiring type with blow by coming from the exhaust. So, I thought I would report mine as well. It cost me $1600 for another engine used with 53k on it and around $1000 total for small parts and labor to put engine in. That's just what I know of today assuming everything works smoothly once they complete it next day or two. This seems to be a common problem and like the other cases my mechanic could not narrow it down to one thing as the cause.

- jqueen, Seneca, SC, USA

problem #4

Aug 092013


  • Manual transmission
  • 145,000 miles

First, I've always do not do my own maintenance. I have a trusted family mechanic who takes care of any my car issues, but I'm also not an idiot, and I'm pretty mechanically inclined.

in June of 2013 my car started making a noise. A knocking/tapping sound from what seemed like the top of the engine that wasn't there before. Very soon after the sound started, I started experiencing large amounts of blow by, smoke was pouring out the tail pipe. No good. I wasn't sure what had happened, and I wanted a diagnosis from a professional so I took it to the Mazda dealer to see if they could tell me what the problem was. No help, they couldn't narrow it down, they did take my 150 dollars for the diagnostics though. There are some known things that kill v-6 6's , spun rod bearings, failed PCV valves causing oil consumption, and catalytic converter failure. I knew that my engine was most likely done. I just didn't know what to do.

So took the car into my family friend who owned his own garage. He ran a compression test, front cyls were at 80, rears at 130. Hmmmm...think there's something wrong with the front of the motor. Made the decision that the motor has to come out. Once the motor was out, we got it on a stand and started disassembling. They got it down to just the short block in about an hour. Then they popped one of the front pistons out, pulled off the ring and put it back in the bore. .20 gap. .20! point two-oh!!! That explains where all the smoke is coming from. So it was clear that we needed to measure the block to make sure it was still usable. Well, long story short. It wasn't. Way out of spec for distortion and taper on the front bank. Rear bank is all in line, front bank is HOSED. So no simple re-ringing here.

At this point I started evaluating my options. New short-block was 5200 bucks, and you couldn't get it anyways. Re-manufactured short-block was 32-3300. I was hoping to get 200K+ out of this car but i will need to settle for 145K that i was able to achieve. Given what i have read on the internet engine failures are pretty predominate with this model care and they occur anything from 50K -150 K miles on those engines. So, even if i were to change out the engine with another used Mazda engine I feel like I'm just rolling the dice to my next failure. Mazda you really disappointed me ...the 626 (1998) that i previously own I got 275K miles out of it and the engine was still running great as the body fell apart around me......that the mazda that i thought i bought when i got my mazda 6, instead I got a piece of crap....

- Cons G., Bolingbrook, IL, USA

problem #3

Nov 092012

MAZDA6 6S 3.0L

  • Automatic transmission
  • 72,530 miles

Sooooooooooooo aside from buying this car, which is used but i am financing, I've had to pay for a complete exhaust replacement, fan module, pcv, flex unions, motor mounts, tranny mounts, cam seal, oil pan gasket etc etc etc. and these go on typically every mazda 6 from 02-06

- jeih332003, Liberty, NY, USA

problem #2

Apr 072011


  • Automatic transmission
  • 65,000 miles

Just paid off the car last year when last week with no warning the car started making a knocking noise, took it to mechanic, he said rod was bad and new engine is needed for cost of 4200, feel not worth the cost and now must look for another vehicle!!! We only had car 4 years, and only has about 65,000 miles!! Found out it has a ford engine, had I known that I would have never bought it in the first place! really disappointed with Mazda, from what i have read this has happened to others and it is due to a $10 pcv valve failing!!! will never own another Mazda again. They should own up to their mistake and issue a recall, no reason it should have failed, it was never without oil!!

- Kim H., Tonawanda, NY, USA

problem #1

Dec 122009

MAZDA6 S 3.0L V6

  • Manual transmission
  • 81,000 miles

Failed without warning. No temp issues, no history of losing oil, no Check Engine Light, nothing. Mazda customer service is adept at deflecting blame, and offered no assistance.

- ahan, Millis, MA, USA

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