Engine Missing around 60mph

[Melkor]

Hey,

When I am driving down the highway and holding around 60mph, the engine "shutters". Perhaps it could be labeled as missing or misfiring or something. I'm not a car expert, but there is a subtle shutter or loss in smooth solid power. It is so subtle you could overlook it, but I pay attention to small details.

Has anyone else experienced this? Are there any mazda mechanics on this forum that have seen this issue? I keep waiting for the check engine light to come on, but perhaps they have a certain tolerance for this....

[Raider]

There is a hesitation issue, and ta TSB for it. ECU reflash. Not really a speed thing, but an rpm range.

[Leeep]

mine still does it after being flashed.
I've learned to ignore it.
I've come to think it's a transmission issue.

[Raider]

Hmm. I am considering flushign the trans fluid anyways. I am at 13K, and I want to be full synth engine and trans.

[AWDGalaxy]

I have also had the ECU flash and I still have the shutter as well. I took mine to the dealer and they claim that it does not shutter and that I am feeling road vibration.

[AWmustang]

I have also had the ECU flash and I still have the shutter as well. I took mine to the dealer and they claim that it does not shutter and that I am feeling road vibration.

I have had something similar happen in a previous car. So I made them take my car and one identical to it out on the same roads back to back.

The car was fixed the next day.

[Alpha Wolf]

I have noticed it as well and I also have the reflashed ECU..

It is not the engine..

It is the ECU not being able to decide to down shift or not and it feels like it is going in and out of gear. I popped in manual and presto no stumbling... You might wish to try this and see if this is the case on your car as well.

So now when I get up to speed on the highway I routinely put it in manual so it will not constantly try to downshift into 5th or 4th...

[rexercx7]

I wish I could just go 60MPH!:)

On our freeways around here you'd be run over by a truck going 65 or more if you were to go 60MPH, even in the far right lane. There are so many trucks in SoCalifornia on the freeways, it's a scary thing, a safety thing. I just go with the flow of traffic in the middle lane, and it's usually 70-75MPH seemingly using almost no throttle at all. My CX-7 just seems to have so much power.

There's no option, at least no safe option, to be going 60MPH on SoCalifornia freeways.

Kindest regards,
rexercx7:cool:

[rexercx7]

I have noticed it as well and I also have the reflashed ECU..

It is not the engine..

It is the ECU not being able to decide to down shift or not and it feels like it is going in and out of gear. I popped in manual and presto no stumbling... You might wish to try this and see if this is the case on your car as well.

So now when I get up to speed on the highway I routinely put it in manual so it will not constantly try to downshift into 5th or 4th...

That's an excellent point, and observation. I also only use manual mode on the freeway. Perhaps that's why I've never noticed the "hesitation" as the ECU tries to decide to downshift, or not.

Kindest regards,
rexercx7:cool:

[Alpha Wolf]

I wish I could just go 60MPH!:)

On our freeways around here you'd be run over by a truck going 65 or more if you were to go 60MPH, even in the far right lane. There are so many trucks in SoCalifornia on the freeways, it's a scary thing, a safety thing. I just go with the flow of traffic in the middle lane, and it's usually 70-75MPH seemingly using almost no throttle at all. My CX-7 just seems to have so much power.


Kindest regards,
rexercx7:cool:
:D


Besides, once going, the CX7 is nearly idling at 70 mph. It is so easy to just cruise along much faster.....

Up here there are roads where if you are NOT DOING 80mph or faster you best be in the slow lanes as the traffic flows at 85mph + at times...

Yugo drivers need not try to drive these roads..... :D

[Melkor]

Thanks for the replies guys. I will try the manual mode to see if the hesitation goes away.

And ya, if I go on up to 70-75 the problem goes away. I mostly feel it around 60mph.

[Melkor]

Ok, I tried the manual mode test and it still does the shutter/misfire thing. I will eventually take this into the dealer.

[Melkor]

I just had the TCM reflash. Alpha Wolf has another thread on this describing it as transmission stuttering. It is predominant around 60mph under light acceleration. I called it misfiring in the thread, but that just shows my ignorance. It is more accurately the transmission stuttering or surging.

Anyways, after the reflash, I have only done a little driving.
My impression is the transmission just behaves different. Yes, the main stuttering problem is a little better, but every once in a while I can still feel the transmission stutter, just under different conditions. I will say the transmission is improved with the flash however. Please post your comments if you have had this reflash. Can you also still feel a little transmission stutter once in a while?