2011 CX-9 Stutter / jitter when accelerating at cold startup and highway speeds...Ideas?!

Wife complained about a stuttering that took MONTHS for me to experience first hand. It's exactly as I stated -- a stutter or jitter that appears to be engine based, and only happens with a cold engine that's accelerating at highway speeds (probly starts at 40 or 50 mph speeds and up). After 10 to 15 minutes, the issue disappears, but it's definitely something I'd like to remedy ASAP.

Any ideas where to start looking?!

Thanks in advance!!
 
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Mazda CX-9 Grand Touring 2016
How many miles on that transmission? Has the fluid been changed regularly?

You might be nearing the end of the life of the transmission. If the fluid has not been changed regularly, say every 50,000 miles, don't change it now, that'll make things worse. You can try adding a bottle of LubeGard transmission protectant. That can help with the shudder. And check the cost of a transmission replacement vs. replacing the car. Check with a transmission specialty shop in your area.
 
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2010 CX-9 GT
Wife complained about a stuttering that took MONTHS for me to experience first hand. It's exactly as I stated -- a stutter or jitter that appears to be engine based, and only happens with a cold engine that's accelerating at highway speeds (probly starts at 40 or 50 mph speeds and up). After 10 to 15 minutes, the issue disappears, but it's definitely something I'd like to remedy ASAP.

Any ideas where to start looking?!

Thanks in advance!!

There are several threads on be the forum that discuss a hesitation at speed that sounds like what you are describing. Based on those threads, I'd recommend checking the spark plugs and the ignition coils first. If that doesn't help, the VVT actuators have been known to act up and cause a hesitation.
 
Thanks, jal142!! Pretty much what I expected, minus the VVT actuators. Definitely seems more like an engine issue than a trans issue.

We changed the trans fluid at least 20k or 30k mi ago, as soon as it would start jerking in and out of park *and* I realized this vehicle doesn't have a transmission filter!! Disappointing realization....

Hoping it's not then VVT actuators, as I only run synthetic.... but I'm sure that won't help against all manufacturer flaws. I guess I'll just order some new plugs and then try to ohm out the coil packs and see if one is off. . .
 
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2014 Ford Explorer Sport, 2009 CX9(Wife's)
Check plugs/coils.

My wife's CX9 had a similar stutter, most noticeable at highway speeds at lower rpm and under load with torque converter locked up.
It was fairly violent when it did it.

Initially I thought it was transmission related, but I decided to buy a bluetooth OBDII reader and Torque app to monitor misfires.

Found that 1 or 2 of the front cylinders would increase in misfire counts when it was stuttering.
I replaced plugs on the front 3 cylinders and issue went away.

I know there was an issue with some CX9's that pinged when cold, but was fine once it warmed up.

My wife's pinged when cold, but it didn't hesitate when it was cold....or at least we were never going fast enough when it was cold to experience the hesitation. By the time we got on the highway, engine was at least warm.
 
Odrapnew... I have the Torque app but never noticed a misfire count. Will definitely have to look into that. Good tip!
 
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2014 Ford Explorer Sport, 2009 CX9(Wife's)
Odrapnew... I have the Torque app but never noticed a misfire count. Will definitely have to look into that. Good tip!

It's been a while since I used it, but I think I had to run the fault code scan while driving the vehicle.
It would cycle through scanning the different parameters and then repeat over and over.

I think it took a few minutes to cycle through all the parameters and then restart the scan.

After a few cycles, I looked at the misfire counts for each cylinder and noticed 1 or 2 of them increased dramatically after the hesitation occurred.

Note: I believe that feature is only available with the paid version ($5 when I bought it years ago).