I'm sick...think my car is developing "The Stumble"
#16
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I think it's still worth checking the clutch before assuming it's an engine problem that's just appeared.
The last time I had a car which needed a new clutch, the obvious indicator was that the tach wasn't steady when cruising at a steady speed. It tended to fluctuate up and down. Probably your best check is to take it up to high gear on a highway and see how it behaves.
The last time I had a car which needed a new clutch, the obvious indicator was that the tach wasn't steady when cruising at a steady speed. It tended to fluctuate up and down. Probably your best check is to take it up to high gear on a highway and see how it behaves.
#17
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I've had stumble since day zero. It was always there. Is the stumble only in 1st gear between 2 and 3k rpm? If so, I wouldn't suspect the clutch. Many people have their clutch last well over 100k miles. Your car is still low mileage in my book.
Although I agree that it is odd that you had not experienced the stumble before. It is normal.
Although I agree that it is odd that you had not experienced the stumble before. It is normal.
#18
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Originally Posted by Gus_Smedstad
I think it's still worth checking the clutch before assuming it's an engine problem that's just appeared.
The last time I had a car which needed a new clutch, the obvious indicator was that the tach wasn't steady when cruising at a steady speed. It tended to fluctuate up and down. Probably your best check is to take it up to high gear on a highway and see how it behaves.
The last time I had a car which needed a new clutch, the obvious indicator was that the tach wasn't steady when cruising at a steady speed. It tended to fluctuate up and down. Probably your best check is to take it up to high gear on a highway and see how it behaves.
Originally Posted by subshooter
I've had stumble since day zero. It was always there. Is the stumble only in 1st gear between 2 and 3k rpm? If so, I wouldn't suspect the clutch. Many people have their clutch last well over 100k miles. Your car is still low mileage in my book.
Although I agree that it is odd that you had not experienced the stumble before. It is normal.
Although I agree that it is odd that you had not experienced the stumble before. It is normal.
If I put it in Sport, it's almost non-existent.
I wonder if it's an active engine mount going bad? Or the trans mount failing?
#19
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I also experience this on my 15 C2 MT w/12k miles. I'm bringing it to the dealer for the 2yr service and will bring it up to the SA. It's hard to believe it's normal. Didn't have this issue with my previous 997 tt.
#20
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We've had two (2) active engine mounts go bad on my wife's 2015 Cayman S, and didn't feel a thing. In both cases the only reason we knew there was a problem was that the multi-function display popped up the PADM error. I'd assume if you can feel such a thing, it would wouldn't depend on gearing, but on engine RPM.
#21
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So I have a 2013 C4S MT. I've driven it 22k miles now. around a year ago, I had this weird pause at low RPMs as well. It was very clearly there. It sounds similar to what you're describing.
I had been putting a lot of low RPM miles in (putting around town). So I put in a few really hard drives on the highway, WOT, pulling hard (with appropriate coolant and oil temps of course). Maybe 20-30 miles. Within a few days, that pause disappeared.
I always drive in Sport Plus mode. I have PSE.
Perhaps it's some kind of software accommodation to your driving style?
give it a shot and get back to us!
W
I had been putting a lot of low RPM miles in (putting around town). So I put in a few really hard drives on the highway, WOT, pulling hard (with appropriate coolant and oil temps of course). Maybe 20-30 miles. Within a few days, that pause disappeared.
I always drive in Sport Plus mode. I have PSE.
Perhaps it's some kind of software accommodation to your driving style?
give it a shot and get back to us!
W
#22
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Originally Posted by wwspeeds
So I have a 2013 C4S MT. I've driven it 22k miles now. around a year ago, I had this weird pause at low RPMs as well. It was very clearly there. It sounds similar to what you're describing.
I had been putting a lot of low RPM miles in (putting around town). So I put in a few really hard drives on the highway, WOT, pulling hard (with appropriate coolant and oil temps of course). Maybe 20-30 miles. Within a few days, that pause disappeared.
I always drive in Sport Plus mode. I have PSE.
Perhaps it's some kind of software accommodation to your driving style?
give it a shot and get back to us!
W
I had been putting a lot of low RPM miles in (putting around town). So I put in a few really hard drives on the highway, WOT, pulling hard (with appropriate coolant and oil temps of course). Maybe 20-30 miles. Within a few days, that pause disappeared.
I always drive in Sport Plus mode. I have PSE.
Perhaps it's some kind of software accommodation to your driving style?
give it a shot and get back to us!
W
#24
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My question for you folks who have the stumble, do you notice it when your driving your car normally or do you have to specifically run it slowly through that specific rev range to get the stumble?
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
#25
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Needsdecaf! Man, was reading this thread and didn't even realize it was you! Sucks to see you're being met with this after moving from the F10.
Any link or quick description of what this "stumble" is? I'm assuming it's not a catastrophic failure type of issue, more so an annoyance (i.e not something that will break the car, but something that affects the way it drives).
It only related to 991's or also 981's?
Any link or quick description of what this "stumble" is? I'm assuming it's not a catastrophic failure type of issue, more so an annoyance (i.e not something that will break the car, but something that affects the way it drives).
It only related to 991's or also 981's?
#26
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Yeah...the pull to the right that required a new steering column. The constant drifting while driving straight...no wait, that's BMW's EPS doing "wind correction". The terrible Bluetooth mics. The 250 RPM idle surge, the ridiculous Nav, and finally the nasty throttle tip-in lag that more than once almost caused me to get into an accident. That ultimately lead to me to getting rid of the car. Compared to that, this stumble is a walk in the park. That was downright unsafe.
The nav....there just are no words to describe how stupid it was. So I will let the pictures do the talking.
Like this one, that tried to get me to pull a u turn.....in the middle of a divided road.
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Or this one that thought driving 1/4 mile on the highway wasn't fun, so it wanted me to get off, do a u-turn, and get back on.
The nav....there just are no words to describe how stupid it was. So I will let the pictures do the talking.
Like this one, that tried to get me to pull a u turn.....in the middle of a divided road.
![Name: 2848ff36.jpg
Views: 2950
Size: 288.3 KB](https://rennlist.com/forums/attachments/991/1191275d1501201135-i-m-sick-think-my-car-is-developing-the-stumble-2848ff36.jpg)
Or this one that thought driving 1/4 mile on the highway wasn't fun, so it wanted me to get off, do a u-turn, and get back on.
![Name: 8476d6db.jpg
Views: 2950
Size: 294.1 KB](https://rennlist.com/forums/attachments/991/1191276d1501201135-i-m-sick-think-my-car-is-developing-the-stumble-8476d6db.jpg)
#27
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1) Normal driving under light throttle. Around town, as I accelerate through ~2600 rpm I'll get it. Occurs probably 75% of the time. For some reason, it never occurs in 1st gear. Drive it aggressively and you'll never feel the slightest hesitation.
2) On an uphill grade, if I hold the rpm at or near 2600, I'll get a noticeable stumble. Imagine a micro second of bad fuel.
Chances are, if someone else were to drive my car, it would take a week or so for them to notice the problem. But once you know it's there, it's impossible to ignore.
#28
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What models has the "stumble" been reported on? 911 and Cayman only?
#29
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My question for you folks who have the stumble, do you notice it when your driving your car normally or do you have to specifically run it slowly through that specific rev range to get the stumble?
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
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#30
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My question for you folks who have the stumble, do you notice it when your driving your car normally or do you have to specifically run it slowly through that specific rev range to get the stumble?
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
On a related note, wasn't there another thread on here where someone recently (within the last few months) mentioned a fix they found? I could have sworn I read someone posting about chasing this thing all over the motor and finally finding something that had been installed wrong, IIRC two electrical connectors that were swapped during install at the factory.
That "fix" was an issue with the PSE plug and something related to the coolant being swapped. That member had his PSE installed after purchase. What he was experiencing was likely different than the stumble, and caused by the install.
Needsdecaf! Man, was reading this thread and didn't even realize it was you! Sucks to see you're being met with this after moving from the F10.
Any link or quick description of what this "stumble" is? I'm assuming it's not a catastrophic failure type of issue, more so an annoyance (i.e not something that will break the car, but something that affects the way it drives).
It only related to 991's or also 981's?
Any link or quick description of what this "stumble" is? I'm assuming it's not a catastrophic failure type of issue, more so an annoyance (i.e not something that will break the car, but something that affects the way it drives).
It only related to 991's or also 981's?
Below is the best way to describe what it is. But if you want a huge reading assignment...https://www.6speedonline.com/forums/...-2500-rpm.html
I notice the stumble in two instances:
1) Normal driving under light throttle. Around town, as I accelerate through ~2600 rpm I'll get it. Occurs probably 75% of the time. For some reason, it never occurs in 1st gear. Drive it aggressively and you'll never feel the slightest hesitation.
2) On an uphill grade, if I hold the rpm at or near 2600, I'll get a noticeable stumble. Imagine a micro second of bad fuel.
Chances are, if someone else were to drive my car, it would take a week or so for them to notice the problem. But once you know it's there, it's impossible to ignore.
1) Normal driving under light throttle. Around town, as I accelerate through ~2600 rpm I'll get it. Occurs probably 75% of the time. For some reason, it never occurs in 1st gear. Drive it aggressively and you'll never feel the slightest hesitation.
2) On an uphill grade, if I hold the rpm at or near 2600, I'll get a noticeable stumble. Imagine a micro second of bad fuel.
Chances are, if someone else were to drive my car, it would take a week or so for them to notice the problem. But once you know it's there, it's impossible to ignore.