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Engine stumble/hesitation around 2500 RPM?

 
  #16  
Old 02-18-2013, 12:09 PM
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Originally Posted by 991s View Post
Took my car back to the dealer this morning and the tech came for a drive with me and he could also feel & hear the "stumble/hesitation". He plugged my car into his diagnostics and, of course, no faults or CEL's so I was told to drive it and see if it gets better or worse or goes away!

Techs nowadays don't seem to be able to "think" to try to figure out problems. They just rely 100% on their PC's and diagnostics and if there aren't any fault codes then everything must be fine. In reality it's not.

This was a wasted trip and the outcome was as I expected. However, my engine hestitation remains. Frustrated.
That's why I like Boardwalk in Dallas; they don't quit until it's fixed. You needed a trip to Dallas didn't you? In the meantime, you might give Cliff Blackshear (head tech) a call there to see if he's ever heard of the problem.

ChuckJ
 
  #17  
Old 02-18-2013, 12:31 PM
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Here's another possible cause for the stumble/hesitation (post#9) that illustrates the difficulties with no codes/cel:

https://www.6speedonline.com/forums/...ml#post2540694
 
  #18  
Old 02-18-2013, 01:37 PM
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Originally Posted by ChuckJ View Post
That's why I like Boardwalk in Dallas; they don't quit until it's fixed. You needed a trip to Dallas didn't you? In the meantime, you might give Cliff Blackshear (head tech) a call there to see if he's ever heard of the problem.

ChuckJ

Thanks, I'll give him a call. All my local dealers are the same, whether it be MB or Porsche or BMW - if it doesn't throw a code they can't or won't do anything.
 
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Old 02-18-2013, 01:52 PM
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Originally Posted by runner1021 View Post
Here's another possible cause for the stumble/hesitation (post#9) that illustrates the difficulties with no codes/cel:

https://www.6speedonline.com/forums/...ml#post2540694

Thanks, I appreciate the link and it sounds similar to my problem. I thought it could be the MAF sensor but the tech doesn't share my opinion!!
 

Last edited by 991s; 02-19-2013 at 08:23 AM.
  #20  
Old 02-20-2013, 02:17 PM
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Its got to be related to the previous work that was done....
 
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Old 02-20-2013, 02:25 PM
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Originally Posted by G997 View Post
Its got to be related to the previous work that was done....
I don't know if it is or isn't but I suspect the same thing. I wish I knew for sure.

I didn't feel the stumble before the last repair because I was/am breaking the car in and was driving only in auto mode. In auto the car changes gear before the revs reach 2500 rpm under light throttle. Once I got the car back and got a few more miles on it I starting drivng in manual mode and that's when I started to feel the stumble.
 
  #22  
Old 03-04-2013, 07:21 PM
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I too have the stumble between 2500 and 3000 RPM on my recently delivered C2S. I remembered seeing this post and ignoring it when I saw it, but now it's happening to my car too, so I was checking to see if anyone had a solution yet.
 
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Old 03-05-2013, 01:57 AM
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I too have a stumble at 2500 RPM when drive the PDK in manual mode and not pressing the throttle hard. It is intermittent. Will call the local dealer for an appt.
 
  #24  
Old 03-05-2013, 08:42 PM
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Checked today. No stumble on the base anywhere between 2500 and 3000
 
  #25  
Old 04-13-2013, 07:43 AM
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So I mentioned the hesitation my C2S has between 2600 and 3000 RPM at moderate load on a Porsche survey I received, and the next day got a call from my dealer. I explained what I was noticing and although he was quite surprised I could feel it, he said that it was a "feature" of the PDK, but encouraged me to bring it in once my break-in was over. I have a feeling this is going nowhere, but I'll bring it in to give them a chance to see if they feel it too.

Has anyone else had this addressed by their dealer?
 

Last edited by mtony; 05-03-2013 at 05:07 AM.
  #26  
Old 04-13-2013, 04:58 PM
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Originally Posted by 991s View Post
Still breaking my engine in and taking it easy, however, I notice that when I'm in manual mode (PDK) and accelerating in 2nd (gently) the engine hesitates/stumbles around 2500 rpm but it's fine once past 3000 rpm. I don't notice it in any other gear. Is this normal? Is it the throttle bodies opening? Or is it a fueling/ECU issue?

Anyone else seen this issue?

I had this when the car was brand new, under 100 miles. Though it was the Vario-cam, like others suggested

Frankly, I'd forgotten about it. Now at 700 miles, I haven't noticed it. Seems to have gone away.


As for the techs not seeming to care about solving the problem: they have no choice. The engineers at Porsche and their diagnostic systems are pretty sophisticated. A local tech, no matter how well trained, who decides to go rogue and become an artist instead of a scientist, is crossing the line. He has no incentive to do that. Doing something out of the box at this early point could actually damage your engine.
 
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Old 04-14-2013, 05:28 PM
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The car most likely has a noisy sensor. Since it's related to RPM, the most likely culprit is any sensor which measures the camshaft position. The tech should have a history of the most replaced sensor on the car. If the most replaced sensor is related to the camshaft, start there.
 
  #28  
Old 05-02-2013, 08:45 PM
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Originally Posted by mtony View Post
I too have the stumble between 2500 and 3000 RPM on my recently delivered C2S. I remembered seeing this post and ignoring it when I saw it, but now it's happening to my car too, so I was checking to see if anyone had a solution yet.
I'm experiencing it when I accelerate in 4th 5th or 6th gear between 2500-3500 rpm. Still have 400 miles to go on break in. Really haven't noticed it in 2nd or 3rd. Thought I would give this thread a bump to see if anyone had gotten an answer. More annoying than anything else, that is unless it gets progressively worse.
 
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Old 05-03-2013, 05:08 AM
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Still haven't taken it in. Waiting for the break-in to be over. Definitely hasn't gotten worse, but no better either.
 
  #30  
Old 05-03-2013, 05:38 AM
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Originally Posted by Cutters68 View Post
I'm experiencing it when I accelerate in 4th 5th or 6th gear between 2500-3500 rpm. Still have 400 miles to go on break in. Really haven't noticed it in 2nd or 3rd. Thought I would give this thread a bump to see if anyone had gotten an answer. More annoying than anything else, that is unless it gets progressively worse.
Is this when it is warm or cold? And is it a smooth reduction of power surge or misfire?

ChuckJ
 

Last edited by ChuckJ; 05-03-2013 at 05:40 AM.

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