I have an Mazda 3 07' GT 5speed, and find that it is running rough. I sat in an friends' 06 3 GT automatic, and found it ran a lot smoother.

I've pointed this out to the dealer twice now, and they have said they can find anything, but it doesn't run like a new car, it only has 10,000km on it.

It has not been redlined, but has been close only 3 times, other than that i usually never put it over 4700 rpm. and on average shift around 3500, so I don't think that is driving it too hard. Any suggestions? or anyone else find this? Can't blame the dealer, as they don't drive it all the time, and probably can't tell one from the next.

 

I wouldn't be shocked if they used different mounts for the automatic and manual models. I know on the 3rd gen Protege the passenger side and front mounts were different, the automatics having more stuff bolted on to reduce noise, vibration, and harshness.

Is it just 'rough' in the sense that you can really feel the engine a bit more (i.e. vibrations), or is the sound of the idle a little rough too? New spark plugs could help, but 10,000kms is sooooooo low mileage for that to be the cause. Check the basics like the plugs, the air filter, etc before diving into further investigation.

good luck, let us know if you figure anything out!

 

Thanks, I will check into it more, I wonder if its just not the mounts, i have to find someone with an 07 GT 5 Spd and see, ha ha. They adjusted something already on the idle - probably on throttle body, but still doesn't feel like a slick new car.

 

I know there was a revision to the throttle body, but I'm not sure if it was in response to idle roughness concerns. Someone on here who was having an issue with uncontrollable acceleration and deceleration just had the throttle body replaced with a revised unit.