Problem w/ new C4S: Car hesitates on acceleration only when newly shifted to "Drive"
08-04-2007, 01:42 PM
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Problem w/ new C4S: Car hesitates on acceleration only when newly shifted to "Drive"
Ok, here is the issue:
Purchased a new C4s last week. Tiptronic. The car is in break-in mode, with about 450 miles on the odometer.
Last night, I was making a three point turn. During this common manuever, I put it "reverse" and then back to "drive" so that I can drive off. The problem: when I placed it into "Drive" and pressed the gas, the car had a 1-2 second hesitation before actually moving. The revs shot up and the car stood still. Only after a second or two did the car actually get going to catch up with the throttle.
I have found out that this problem ONLY occurs upon the first time shifting to "Drive". For example, say you have been driving the car in "Drive" for 15 minutes, and come to a stop at a red light. When the light turns green and the gas is pressed, the car will respond immediately. However, if at that stop light I had put the car in "Park" and then shifted back down to "Drive" to take off, the car would hesitate for a few seconds (almost like it was in "Neutral", and finally popped into "Drive")
I assume this is transmission issue: the car is not fully engaged into gear after shifting to "Drive". Who knows....maybe the car is too new and its still getting adjusted via ECU.
Thoughts, comments...thanks.
Purchased a new C4s last week. Tiptronic. The car is in break-in mode, with about 450 miles on the odometer.
Last night, I was making a three point turn. During this common manuever, I put it "reverse" and then back to "drive" so that I can drive off. The problem: when I placed it into "Drive" and pressed the gas, the car had a 1-2 second hesitation before actually moving. The revs shot up and the car stood still. Only after a second or two did the car actually get going to catch up with the throttle.
I have found out that this problem ONLY occurs upon the first time shifting to "Drive". For example, say you have been driving the car in "Drive" for 15 minutes, and come to a stop at a red light. When the light turns green and the gas is pressed, the car will respond immediately. However, if at that stop light I had put the car in "Park" and then shifted back down to "Drive" to take off, the car would hesitate for a few seconds (almost like it was in "Neutral", and finally popped into "Drive")
I assume this is transmission issue: the car is not fully engaged into gear after shifting to "Drive". Who knows....maybe the car is too new and its still getting adjusted via ECU.
Thoughts, comments...thanks.
08-04-2007, 04:16 PM
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Originally Posted by Shant
Ok, here is the issue:
Purchased a new C4s last week. Tiptronic. The car is in break-in mode, with about 450 miles on the odometer.
Last night, I was making a three point turn. During this common manuever, I put it "reverse" and then back to "drive" so that I can drive off. The problem: when I placed it into "Drive" and pressed the gas, the car had a 1-2 second hesitation before actually moving. The revs shot up and the car stood still. Only after a second or two did the car actually get going to catch up with the throttle.
I have found out that this problem ONLY occurs upon the first time shifting to "Drive". For example, say you have been driving the car in "Drive" for 15 minutes, and come to a stop at a red light. When the light turns green and the gas is pressed, the car will respond immediately. However, if at that stop light I had put the car in "Park" and then shifted back down to "Drive" to take off, the car would hesitate for a few seconds (almost like it was in "Neutral", and finally popped into "Drive")
I assume this is transmission issue: the car is not fully engaged into gear after shifting to "Drive". Who knows....maybe the car is too new and its still getting adjusted via ECU.
Thoughts, comments...thanks.
Purchased a new C4s last week. Tiptronic. The car is in break-in mode, with about 450 miles on the odometer.
Last night, I was making a three point turn. During this common manuever, I put it "reverse" and then back to "drive" so that I can drive off. The problem: when I placed it into "Drive" and pressed the gas, the car had a 1-2 second hesitation before actually moving. The revs shot up and the car stood still. Only after a second or two did the car actually get going to catch up with the throttle.
I have found out that this problem ONLY occurs upon the first time shifting to "Drive". For example, say you have been driving the car in "Drive" for 15 minutes, and come to a stop at a red light. When the light turns green and the gas is pressed, the car will respond immediately. However, if at that stop light I had put the car in "Park" and then shifted back down to "Drive" to take off, the car would hesitate for a few seconds (almost like it was in "Neutral", and finally popped into "Drive")
I assume this is transmission issue: the car is not fully engaged into gear after shifting to "Drive". Who knows....maybe the car is too new and its still getting adjusted via ECU.
Thoughts, comments...thanks.
08-04-2007, 05:04 PM
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Originally Posted by greenie
I wonder if this is a software issue. If it is, the dealer can re-program the tranny to rectify this problem.
I've been playing around with it today. The problem occurs only within a few seconds after shifting to "Drive". So, if I move the shifter to "Drive", wait 10 seconds, and apply the gas, the hesitation doesn't appear.
Perhaps its just the way the transmission is set from the factory...???
08-04-2007, 10:13 PM
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Originally Posted by Shant
Yes, perhaps it is software.
I've been playing around with it today. The problem occurs only within a few seconds after shifting to "Drive". So, if I move the shifter to "Drive", wait 10 seconds, and apply the gas, the hesitation doesn't appear.
Perhaps its just the way the transmission is set from the factory...???
I've been playing around with it today. The problem occurs only within a few seconds after shifting to "Drive". So, if I move the shifter to "Drive", wait 10 seconds, and apply the gas, the hesitation doesn't appear.
Perhaps its just the way the transmission is set from the factory...???
shant, if I were you, i wouldnt assume that it should be that way. Usually, when we think something aint right, we are proven to be correct. Tell the dealer that you want the tranny re-programmed. Its a nothing type of "repair" and they shouldnt resist. My 07 BMW coupe started "lurching'(its a TIP as well) just as I am stopping but if I put it in "S" it doesnt do it. I called the dealer, told them what it was doing and that I thought it need to be programmed and they agreed. It goes in next Wed.
08-06-2007, 03:44 PM
#5
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Like every automatic, it takes a beat or two for gears to engage when changing directions, even if you flick it into 'D' quickly. Don't step on the gas until engagement is complete.
If it is really taking a full three seconds to engage, there may be a problem.
If it is really taking a full three seconds to engage, there may be a problem.
08-06-2007, 03:51 PM
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Originally Posted by Alan Smithee
Like every automatic, it takes a beat or two for gears to engage when changing directions, even if you flick it into 'D' quickly. Don't step on the gas until engagement is complete.
If it is really taking a full three seconds to engage, there may be a problem.
If it is really taking a full three seconds to engage, there may be a problem.
08-06-2007, 11:20 PM
#7
Race Director
It's nothing to do with an auto or manual tranny. The 997S does this and it is well noted on this board and others. Mine does this every once in a while but never at the dealer.
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08-07-2007, 01:08 AM
#8
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My 6 speed 07 S will hesitate occasionally after the car has been driven to FOT then sits for about an hour and right as I rev it to pull away I get a mis, then after it runs for a minute or two it goes away. The dealership blamed it on fuel quality but my other German cars never have this problem no matter the brand of gas (we use Shell, Mobil or Chevron , all 93). I wish Porsche would just fess up and get this issue resolved.
08-07-2007, 01:38 AM
#9
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mdrums and 500, read his post carefully...he is simply not allowing the auto tranny to engage when going into 'D' from 'P' or 'R'. The Tiptronic's shift lever has a very tight pattern, and it's easy to flick it from 'P' to 'R' to 'D'...but as I mentioned earlier, the transmission needs a beat or two to engage.
He's getting used to his new car...don't lead him to believe there's something wrong with it...
He's getting used to his new car...don't lead him to believe there's something wrong with it...
08-07-2007, 09:31 AM
#10
Race Director
Alan, yep you're right he needs to want for it to engauge in drive. I thought he was talking about the other deal ya know? Read the post too fast! see ya, Mike
08-07-2007, 08:07 PM
#12
Don't know about the 6-speed (and don't care) but this is typical of Mercedes auto transmisions. Every MB that I have had experienced a delay in engaging a forward gear when switched from park. I just figured that MB programs a long time delay to allow the synchros to engage the gear properly.
