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Have a slight stutter/stumble around 15-20mph under light acceleration and around 30-40mph.
Goes away when i let off the gas or slightly press the brake while keeping foot on gas.

Any idea what this could be?? And no i'm not bringing it in to the dealer:)
 

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This has been posted several times over the past year.

What I've determined is that at about 1500 RPM, the transmission "shifts" up to 4th gear, from 1st or 2nd. What you can do is when the engine stutters, press the + paddle on the steering wheel, and look at the gear shown in the center display. Mine always says '4'. You can listen for the 'shifts' prior to this to determine if its shifting from 1 to 4 or 2 to 4.

You should take it to the dealer, at the very least, to document the issue. Many people are having transmission issues, and the more problems that get reported, the better for getting them fixed.
 

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Have a slight stutter/stumble around 15-20mph under light acceleration and around 30-40mph.
Goes away when i let off the gas or slightly press the brake while keeping foot on gas.

Any idea what this could be?? And no i'm not bringing it in to the dealer:)
Mine does exactly the same thing (4500 miles), but not on the Interstate, just "around town" driving. Seems to hunt for the right gear. Every time it happens, my wife reminds me that I traded in a Mercedes ML-350 for the Ascent. Dearly want to love this car, but I'm concerned that this is not only annoying to experience, but might also cause long-term damage to the transmission. I intend to document it when it goes in for its first service, but other than that?

Thanks,
Rob
 

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Mine is noticeable with going down a long slight downgrade, it feels like someone is tapping the brakes, a hesitation. Today I noticed that the tach will tick down as well slightly. Very annoying feeling, still love my car but if I had know what a CVT was I would have passed on the Ascent.
 

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Mine is noticeable with going down a long slight downgrade, it feels like someone is tapping the brakes, a hesitation. Today I noticed that the tach will tick down as well slightly. Very annoying feeling, still love my car but if I had know what a CVT was I would have passed on the Ascent.
That's not the CVT being described by the OP or you. It's either torque converter unlock or turbo wastegate opening.
 

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Why would the waste gate open on a downgrade when presumably there's little exhaust to spin it. It opens to limit boost at higher outputs, right?
 

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Why would the waste gate open on a downgrade when presumably there's little exhaust to spin it. It opens to limit boost at higher outputs, right?
It's variable, not an open or close scenario. I'm not sure of the reasoning, but it was one of the scenarios I was told may be causing it.

I've been meaning to watch boost. But, it would make sense to limit boost for fuel economy under those conditions.
 

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Why would the waste gate open on a downgrade when presumably there's little exhaust to spin it. It opens to limit boost at higher outputs, right?
It's variable, not an open or close onlys wastegate. I'm not sure of the reasoning, but it was one of the scenarios I was told may be causing it, and I'm not sure if it closes, opens, or partially shuts, or, if it's really the wastegate and not the torque converter lock.

I've been meaning to watch boost. But, it would make sense to limit boost for fuel economy under those conditions.

One day, I will have a definitive answer on this, but currently, I do know it's not the CVT itself.
 

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... But, it would make sense to limit boost for fuel economy under those conditions...
What matters for fuel economy is the amount air/fuel getting into the engine, which is controlled by the throttle plates and efi system. Boost isn't controlling what's going on. For a give amount of power: Less boost, open the throttle plate. More boost close it. As long as the amount of air into the engine is the same, boost doesn't matter.
 

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What matters for fuel economy is the amount air/fuel getting into the engine, which is controlled by the throttle plates and efi system. Boost isn't controlling what's going on. For a give amount of power: Less boost, open the throttle plate. More boost close it. As long as the amount of air into the engine is the same, boost doesn't matter.
Boost absolutely affects what's going on. The more boost means more air is being forced into the engines combustion chamber. The more air being forced in requires more gas, even if the air fuel ratio skews more air than normal. .
 
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