Hey guys so two days ago my Mazda 6 was running GREAT, drove it to northglenn from Denver and back, and ft Collins and back to Denver the day before. It was running flawlessly. So after the trip to northglenn and back, my girl drops me off at work and heads to run errands in englewood. I get the dreaded phone call at work 20 minutes later that the car started shaking uncontrolably. Tought it was the tranny by her description. So I go back out to englewood after work and drive it around, not a single issue, she said the check engine light came on before she shut it down, no light, no shaking. So at that point i drove it back to my place in the city, sure enough after 20 minutes of driving (and making the last turn onto my street) the car starts to shake and the check engine light starts to flash. A sure sign of a misfire from what I've read. The shaking happens at low rpm at crusing speed it's not as noticeable, in park it's hardly there but in drive with the e brake on it's there. SO what I'm looking for is confermation that it is a misfire.
A few side notes, this literally happened at 100,000 on the dot, I JUST bought this car 2 weeks ago and I drive ALOT, a thousand miles in two weeks. Changed the oil and had the fluids checked 2 days before this happened as well, the day it happened we switched from regular grade to mid grade gas. I'm running full synthetic oil in the car. it's an automatic 05 Mazda 6s GT wagon and the motor and car is "unmolested" says the Mazda dealer at gateway Mazda so I'm assuming this is an issue based on it having high milage/a fluke. One last thing, almost as soon as this issue started the tranny started to intermittently become on down shifts in random gears, most notably between 3rd and second and 5th and 4th. It's far more rare in sport mode but it is vastly rougher then it was a week ago or even the day before the engine issues. I NEED ADVICE QUICKLY!!!

Thanks
Keegan

Girl driving.

Iliveforum wrote:Hey guys so two days ago my Mazda 6 was running GREAT, drove it to northglenn from Denver and back, and ft Collins and back to Denver the day before. It was running flawlessly. So after the trip to northglenn and back, my girl drops me off at work and heads to run errands in englewood. I get the dreaded phone call at work 20 minutes later that the car started shaking uncontrolably. Tought it was the tranny by her description. So I go back out to englewood after work and drive it around, not a single issue, she said the check engine light came on before she shut it down, no light, no shaking. So at that point i drove it back to my place in the city, sure enough after 20 minutes of driving (and making the last turn onto my street) the car starts to shake and the check engine light starts to flash. A sure sign of a misfire from what I've read. The shaking happens at low rpm at crusing speed it's not as noticeable, in park it's hardly there but in drive with the e brake on it's there. SO what I'm looking for is confermation that it is a misfire.
A few side notes, this literally happened at 100,000 on the dot, I JUST bought this car 2 weeks ago and I drive ALOT, a thousand miles in two weeks. Changed the oil and had the fluids checked 2 days before this happened as well, the day it happened we switched from regular grade to mid grade gas. I'm running full synthetic oil in the car. it's an automatic 05 Mazda 6s GT wagon and the motor and car is "unmolested" says the Mazda dealer at gateway Mazda so I'm assuming this is an issue based on it having high milage/a fluke. One last thing, almost as soon as this issue started the tranny started to intermittently become on down shifts in random gears, most notably between 3rd and second and 5th and 4th. It's far more rare in sport mode but it is vastly rougher then it was a week ago or even the day before the engine issues. I NEED ADVICE QUICKLY!!!

Thanks
Keegan

I'm not a mechanic by anty stretch of the definition, but I would think a misfire would occur even when the car isn't warm. However, if you have a check engine light (CEL) you can take the car to a pars store and read the code. The code should tell you what is going on. One thing to try would be to go back to regular gas...or go to a higher octane. My understanding of higher octane fuel is it resists premature detonation from compression better. (again, see disclaimer in first line). You may also pull the plugs and see if they all look the same. If not, it would be an indication of a misfire. Have the plugs been changed? If not, they are due anyway.

As Shadow said, get the code read. Even if it's not currently active, it should be stored. That's the best starting point. Best yet, you bought it only 2 weeks ago, take it back to Gateway.

Like other's said start with reading the code. Have the plugs ever been replaced?

And FYI, FLASHING check engine light means "turn me off now before engine/catalyst damage"

AuroraAxela wrote:And FYI, FLASHING check engine light means "turn me off now before engine/catalyst damage"

never heard or knew this.

Good to know now though.

Shadowden wrote:I'm not a mechanic by anty stretch of the definition, but I would think a misfire would occur even when the car isn't warm. However, if you have a check engine light (CEL) you can take the car to a pars store and read the code. The code should tell you what is going on. One thing to try would be to go back to regular gas...or go to a higher octane. My understanding of higher octane fuel is it resists premature detonation from compression better. (again, see disclaimer in first line). You may also pull the plugs and see if they all look the same. If not, it would be an indication of a misfire. Have the plugs been changed? If not, they are due anyway.

Solid advice. Report back when you know what error code your car is throwing. I think auto zone can check the error codes for free for you.

It's at the shop as we speak, took it to pep boys and their terddy little code reader couldn't find anything. I'll see what hotchkiss auto finds. Again it ran flawlessly when I drove it 3 miles to their shop this morning. I'll post back with the final answer. Also it was shut down as soon as that light started flashing haha. Thanks guys.

Keegan

Is Gateway not providing any after sales support? I would be heading straight back to the dealer if within 2 weeks my car was hitting limp mode.

The Mazda 6 is designed for regular octane fuel. I'd go back to the low grade. (it's not a lesser grade, it's just what certain engines are designed to run on, to prevent engine knock/retard).

Also, definitely take back to the dealer.

Good luck!