subtle detonation at 60mph....anyone else?

[Lee6]

got my CX-7 last december......basically love it so far

BUT......

there's this detonation thing going on that bothers me.....at least i think it's detonation.......i only notice it on the freeway, between 60 and 70, and only when i give it a little gas (not enough to kick it down a gear...just a little gas)....(did some searching but couldn't find a problem like this)

under those circumstances i feel the whole car shudder a little bit.....it's not pronounced.....there's this subtle shuddering that reminds me of when my camaro had a detonation problem.....an irregular shuddering, and only while accelerating.....my wife didn't notice it at first, but later on she said she could feel it

dealer tried twice to find it/fix it but they "can't duplicate the problem"....they checked the spark plugs and they're ok......guess i'm going to have to go in the car WITH THEM, to the freeway and show them how it behaves

anyone else have this problem?

 

[BlackCherry06]

Not sure if your problem is the same, or maybe a lesser example of the same problem, but this is how my MS6 behaved when I lost a coilpack. I tried to pass someone on the highway (didn't shift down...just gave it a 'goose') and it shuddered and spit, and returned to normal when I backed off. It drove normally if I maintained speed, but resisted acceleration. Eventually I got a blinking CEL and I stopped and had it towed.

Next time you're on the highway, push it hard and see if you can get it to trip a CEL...then your service department will have something to work from.

 

[CX-7owner]

Thats not denotation, thats the TCM, you need to go in and get it reflashed which should cure the shuddering in sixth.

 

[Lee6]

thanks for the coil pack suggestion........as for reflashing, that's probably not it since 2 weeks ago i had her into the dealer for the two exhaust recalls, which entailed a reflash....problem still there

 

[CX-7owner]

Hmm, it doesn't hurt to ask them about the TCM reflash, because they're two different things.

 

[Zoom49]

TCM reflash, they're two different things.

Love is correct, the recalls you had done are a flash for the engine computer.
He is refering to the TCM reflash (Transmission Control Module) This is not a recall but rather a Technical Service Bullitin(hi)

 

[StickShiftCamry]

When it's in 6th gear, the tranny is locked. and say ur speed is low like around 45mph, thats low rpm for 6th gear, now under slight throttle the tranny won't down shift, and try to accelerate while locked in 6th, u get that shuddering. I guess most of u don't drive stick shifts, try accelerating fast while in a high gear with a stick shift, the engine will lug almost asking u to downshift, the CX-7 gives the same sensation w/o the new flash. The new flash softens the lock up converter.

 

[CX-7owner]

They're is a newer flash if you haven't had it, it holds third gear, for a short period of time.

 

[ljmattox]

It really does sound like the TCM reflash TSB needs to be done to this vehicle...mine did the same thing, was reflashed, is now smooth/shudder-free on the highway.

 

[AWmustang]

the new TCM reflash seems much more eager to go into 6th gear when you stop accelerating.

I used to get on the freeway and the car would sit in fourth if i was accelerating and at all... then it would pop into 5th.... and eventually into 6th.

Now as soon as you ease the pressure on the gas pedal... BAM into 6th.

I hope that stays around. I try to keep my lead food driving in manual mode so that the tranny learns economical shifting.... but sometimes you just gotta gun it.