Member Since: 20 Dec 2007
Location: Aberdeenshire
Posts: 27
Reluctant Auto Gearbox
I notice that after the 1st start of the day, my auto gearbox is sometimes reluctant to change into 6th gear until after I have done 7-8 miles. It will change into 6th if I use commandshift.
If I drive the vehicle hard the day previous, then gear changing is as expected and it will go straight to 6th with no delay when I am up to speed. The reluctance to change into 6th gear seems to follow a day when I have driven the vehicle with light throttle. Any thoughts on the possible reason why?
6th Jun 2008 12:46 pm
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
adaptive gearbox
6th Jun 2008 12:47 pm
MiLow
Member Since: 20 Dec 2007
Location: Aberdeenshire
Posts: 27
I did think about the adaptive gearbox, but it is adapting in the wrong manner! If I drive gently then it should change gear earlier, not later!
I've seen this too - only when the engine is cold. I've also noticed that the revs are higher for a given speed while the engine is cold too. My guess would be that the system is trying to maintain slightly higher revs to make the warm-up time as short as possible. This could also mean holding 5th for longer rather than dropping into 6th
I'm sure someone will appear soon with a more accurate answer though......
BTW, Welcome to the Forum The older I get, the more I realise that people confuse wrinkles for wisdom
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6th Jun 2008 12:55 pm
AndrewW
Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
.. which is not me !
But I think someone told me there is a gearbox temperature sensor (seems logical) and presumably the D3 holds 5th to warm it up quicker.... After all the gearbox warms up by the Kenwood (Chef) effect - it doesn't (hopefully) have any local combustion to warm it up
A2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
6th Jun 2008 1:22 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26702
Andrew, almost right . The torque convertor lockup is disabled until the gearbox oil reaches a set temp, hence slightly higher revs to roadspeed ratio. It also inhibits 6th gear until temp is reached. You can override with command shift if you wish.
You will also notice there is no engine braking whatsoever until the set temp is reached. If you let go the accelerator, the revs will drop to idle. When warmed up, the engine overuns and provides engine braking when accelerator is released.
I'm sure someone will appear soon with a more accurate answer though......
Told you so...... The older I get, the more I realise that people confuse wrinkles for wisdom
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Club Orange, Mint or Fruit
Club Walnut Sniffers
6th Jun 2008 2:08 pm
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
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!
. it was adapting to the climate 
