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'New' car paranoia - tip concerns

lofi

Barcelona
Joined
8 Jun 2009
Messages
1,397
Had the 996T a couple of weeks and drive it everyday, it's a very gentle journey to work, low speeds. I am getting paranoid about the behaviour of the autobox when in auto. It seems to let the revs drop very low, unlocking the converter, I think so, so the car is effectively coasting, and then when you add a bit of accelerator the revs climb beyond the point of matching engine and road speed and then drop back a bit at the converter locks to the actual engine/road speed. Now it may be this is normal for a auto of the period (my other auto car is a new seven speed merc) but it sounds odd as the engine noise rises than drops.

Also if the box is in 4th or 5th (always seems to be) and I take my foot off the accelerator and coast the revs will drop to idle speed then 'bounce' back to road speed, I.e. bounce up say 500rpm and then repeat until the road speed slowly subsides and then it will change down.

I guess what I find odd is that when driving gently the box seems to spend a lot of time unlocked so when you apply throttle it has to move the revs back to the road speed point before getting drive.

Manual mode seems to work ok, though I've not used it much, manual override when in auto works ok, kick down is incredibly fast, drops two gears very quickly.

I've been trying to convince myself that it just doesn't like being driven gently and that it is taking a lot of time to adjust from driving an automated manual box via paddles for a couple of years.

Any wise words appreciated.
 
They don't much like being driven gently-the locking in and out is not great. But even new auto are poor sometimes at low speed in performance cars. The M5 (E60) is terrible in town, as are a few Ferrari etc.

I will check mine in a minute as I am going out, but the only thing you mention that I dont think mine does is the revs dropping to idle when lifting off in 4th or 5th. I suppose it depends on the speed, but if for example I am doing 70 in 5th, and lift off, my revs just stay where they are-no drop.

Not much help I know, but if in doubt, get it checked.....you have a warranty I think on yours.
 
I'll try to emulate what you're describing when I'm out today Piers.

My first thoughts are that my C4 definitely didn't behave like that and that I haven't noticed the Turbo doing it either.

That said, other than on motorways or in slow traffic I rarely drive my car in 'D' so may just not have noticed it.

Terry
 
Thanks guys. The dropping to idle speed only happens at low speed, say as a guess 40 in fifth. The car loves to get in those high gears as soon as it can it seems. I'm hopeful it's just the usual paranoia I suffer with a new car. These are very gentle drives in the morning on country roads taking the little one to school so it could just be a combination of being in the most Eco minded gearbox map and being driven like miss daisy. I do have a warranty but I'd like to rule out it being me as over sensitive.
 
If you have a warranty I'd get it seen quick and not bother asking around. The worst they can tell you is "its normal and there's nowt wrong".

When auto boxes start to play up is difficult without an expert to test some of the electronics and I'm no expert and neither am I mechanic. But even I would say it shouldn't behave like that at slow speed - my Merc E-Class (5 speed Tipfunction Auto) is as smooth as silk at low and high speeds and crawling in Manchester city traffic - I keep it in D all the time and it is approaching 100k miles - I had it from new.

Any warranty is there to be used - and I'd use it pronto!
 
Just back from a 30 mile drive which, due to Sunday drivers being out a day early :evil: , allowed me to try and get mine to do the same as yours.

lofi said:
........ behaviour of the autobox when in auto. It seems to let the revs drop very low, unlocking the converter, I think so, so the car is effectively coasting, and then when you add a bit of accelerator the revs climb beyond the point of matching engine and road speed and then drop back a bit at the converter locks to the actual engine/road speed.

Mine definitely did not do this.

Now it may be this is normal for a auto of the period (my other auto car is a new seven speed merc) but it sounds odd as the engine noise rises than drops.

The only way I could emulate this was to stand on the gas pedal really heavily and then lift.

Also if the box is in 4th or 5th (always seems to be) and I take my foot off the accelerator and coast the revs will drop to idle speed then 'bounce' back to road speed, I.e. bounce up say 500rpm and then repeat until the road speed slowly subsides and then it will change down.

:dont know: Mine just wouldn't do that (thankfully) even though I did try a few times.

I guess what I find odd is that when driving gently the box seems to spend a lot of time unlocked so when you apply throttle it has to move the revs back to the road speed point before getting drive.

That sounds more like the car just dropping 'off boost'. Off the throttle it is very quiet and I suppose it does seem a bit like the car is coasting. I put this down to the lack of engine brakes that the low compression ratio gives.

Manual mode seems to work ok, though I've not used it much, manual override when in auto works ok, kick down is incredibly fast, drops two gears very quickly.

'M' is fantastic. 'M' override is ok. I've always found 'D' horrid, except when cruising or stuck in slow moving traffic or jams and I hate using 'kickdown'.

I've been trying to convince myself that it just doesn't like being driven gently and that it is taking a lot of time to adjust from driving an automated manual box via paddles for a couple of years.

Use 'D' for driving gently and 'M' at all other times and you'll be fine. :thumb: Mastering a Tiptronic box takes time but is well worth the effort.

I hope your experiences are just a case of you learning the specific foibles of a 'new' car. I had the benefit of 11k miles 'practice' in my C4 and whilst I find the Turbo a bit different its behaviour is fundamentally the same.
 
Thanks T8, that's very helpful info. I did contact the dealer with whom I have the warranty last week and they said no problem to pop it in and they'd have a look. I wonder if I would benefit from the view of another Indie before I do so? Perhaps 9E who are near me?
 
My C4 tip was silky smooth in auto, only advice I'd give would be to change down on the wheel buttons from high speeds for better control and less wear on the pads etc

It might be worth getting a bloke at OPC to drive it round the block for his opinion + an indie if you've got the energy and compare costs etc I'm no expert but it probably just needs a small adjustment or perhaps fresh oil in the box?
 
FWIW, I used to use D all the time but like you found it always in a very high gear. This generally helped with fuel economy and when it realized you wanted to be 'sporty' and switched to a different programme it was great.

However after speaking to Hartech they said that the tip tends to "old fogey" setting which can put a little more strain on the engine as it can sometimes be labouring a bit.

This probably isn't a big deal and just another Porsche paranoia to worry about :dont know: but I now almost exclusively use M and the buttons to give me control over what gear I'm in unless I'm in heavy traffic or Mway cruising.
 
Regarding your suggestion to maybe get an opinion of another indy such as 9E. Personally I think you are better off taking it straight back to the guys who sold it to you and if there is something wrong, getting them to sort it in no uncertain terms. Then you can take it to 9E for a second opinion if it is all OK or not.

If I had a warranty I'd be in that dealership like lightning.
 
Regarding your suggestion to maybe get an opinion of another indy such as 9E. Personally I think you are better off taking it straight back to the guys who sold it to you and if there is something wrong, getting them to sort it in no uncertain terms. Then you can take it to 9E for a second opinion to ask if it is all OK or not.

If I had a warranty I'd be in that dealership like lightning.
 
Lofi,

I have had this problem.

All autos functioning correctly operate like this when the collant is cold. The torque converter clutch does not begin to lock up until the coolant heats up. It makes progress when cold smoother when coming off the accelerator and allows the engine to rev as drive is directly through the Torque Convertor.

I understand the Torque Convertor Clutch locks up at 16MPH, so what you describe should not happen at speeds greter than this. It felt like running with a slipping clutch if yours is the same.

I had the same problems you describe and progressivly got worse in my case. Manual buttons helped, but using these began to show the same symptons after a while.

Needed a new clutch in my case, but there are a lot of things to check out first. Work well now.

I would take it back and the garage should be able to check for slippage.
 
Bluebird911 said:
Lofi,
I understand the Torque Convertor Clutch locks up at 16MPH, so what you describe should not happen at speeds greter than this. It felt like running with a slipping clutch if yours is the same.

I don't think the clutch slips as once engine and road speed are 'together' it goes fine. What I find is that when I take my foot off the accelerator the clutch seems to unlock and let the revs drop relative to road speed hence when you add accelerator the revs have to climb back to Marc h road speed for the clutch to lock again.

However, I drove it like I meant it this morning and it obviously changed program and dropped gears as I braked into corners etc, still seemed to change up pretty early but it was really quite effective. So I still don't know whether it's just that the car drives in super efficiency mode most of the time or if there is something wrong.

I'm gonna try to get it back to the garage this week.
 
Found this on another site.

For 997 but may be same as 996.
Put the keys in so that all the dash lights come on but don't start
Leave for 60 seconds
turn off
Leave 10 seconds
Start the car.
That should reset the box....

If similar to a 993 tip, you can reset the learned programs by disconnecting the battery.

Worth a try, although your symptoms may not be a program issue.
 
Fuel grade, throttle body position sensor, and Tip modes (Tip learning) are reset as follows:

1) Mechanical cable models Bosch Motronic 5.7: DME reset via battery, manual TB reset
2) eGas Bosch Motronic 7.2: DME reset via battery, TB reset via key
3) eGas Bosch Motronic 7.8: DME reset via battery or key, TB reset via key

Reset via battery requires disconnecting the battery for 30 mins (remember to leave your key in ignition "1" to prevent alarm).

Reset via key requires turning the key to ignition "1" (the position when all the lights are on on the dash) and leaving it for 60+ secs (DO NOT TOUCH THE THROTTLE PEDAL), then switch off for 10+ secs and you should be able to hear a few clicks and whirs from the engine bay as it recalibrates the adaption values.
 

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