Auto GearBox slow pulling off

26sj · #1 09-09-2006, 09:44 AM

I have an 04 facelift 3.0d sport auto.
after diving, for aurguements sake , say you come to a roundabout, you wait for a gap, then when you hit the acclerator pedal there is a half second delay before it move.. its may seem like nothing but when you are sitting there for that short time watching you gap get smaller, then all of a sudden the car bursts into life.
The dealer has checked the car, fitted new turbo and airflow meters, but still the problem persists..

any one else have this problem?
Has anyone got a cure?

thanks

Sponsored Links

LVR · #2 09-10-2006, 08:48 AM

The transmission generally starts you off in 2nd gear as 1st is fairly harsh for stop start traffic. Diesels have the torque to do this better as well.

In order to get it into 1st, and fairly leap off the line you have to let it know you want that by doing one or both of two things.

The trans and engine computers measure the speed of throttle depression and pressure depth to see what the situation is.... ie quick start. Try a back street start and just smash the pedal. Your car will leap off the line. Do it a couple of times if you need to and see the changes in response.

If you are still moving through a roundabout (particularly at low speed) and have been using conservative throttle, it is then checking cornering speed, brake pressure, yaw rate and a number of other factors. If you are at a fairly sedate pace then it will not do anything other than maintain an economy mode ie 2nd gear start.

My wife could be described as having a heavy foot in our X5 3.0 and it flies.. whereas my 4.8 is a slug off the line (guess who's the conservative one hey?)

The other thing you can try is driving through the same area in sport mode to see if it is indeed the trans 'thinking' as I descibed above. If it is the trans, you just have to drive it harder so it adapts to your style of driving.

If not then I am sure some diesel owners can offer further advice.

john348 · #3 09-10-2006, 10:30 AM

THis is a very very common problem. There is a rumour that there is a software fix but it has had mixed results. Mine does it a lot and I cannot find a common theme like hot or when slowing from a spirited run or cruising etc. The official line is that it is traction control etc kicking in to preserve the engine and get the best traction but as it is not moving at the time I told them this is %&££it. I spoke to a salesman and he had sympathy as it happened to him when he borrowed an X5. I will be taking it up with them again at the impending service and will try to get the latest software and I will let you know if it fixes anything.

John

chris_barry · #4 09-10-2006, 10:51 AM

I get this in my Aussie 3.0d. I thought it was turbo lag as it only happens from if the engine has been at idle for a few seconds. If the engine has been under load from driving up to the intersection the response is instantaneous.

Chris.

LVR · #5 09-10-2006, 11:02 AM

Quote:

Originally Posted by chris_barry

I get this in my Aussie 3.0d. I thought it was turbo lag as it only happens from if the engine has been at idle for a few seconds. If the engine has been under load from driving up to the intersection the response is instantaneous.

Chris.

Have either of you tried what I suggested? When I get into my wifes' car it leaps off the line at every start like a scalded cat.

The cars are designed to measure the signals from all the inputs I mentioned and then compare them against what it has recorded about your previous driving. As it takes inputs from suspension and stability systems, a software update for the trans alone is generally unsuccessful, and the whole system needs to be updated.

either that, or drive like my wife does

26sj · #6 09-10-2006, 11:15 AM

i take on board what ya saying, but,
i can floor the pedal so that i get a click off the pedal stop, and take my foot off, admittedly in an instant, but in that time the car does not move an inch.. its like the drive by wire not sending signals fast enough

AzNMpower32 · #7 09-10-2006, 11:20 AM

Quote:

Originally Posted by 26sj

i take on board what ya saying, but,
i can floor the pedal so that i get a click off the pedal stop, and take my foot off, admittedly in an instant, but in that time the car does not move an inch.. its like the drive by wire not sending signals fast enough

Possibly. Did you try putting it in Sport mode? that way, you will always start off in 1st gear.

If you want to see how electronic throttle responds try this. In a safe place, put the car in N. Then blip the throttle. There's a split second lag (very slight though) on my gasoline X3; if the response is really awful, then 1) its a diesel thing or 2) maybe a software fix?

john348 · #8 09-10-2006, 11:27 AM

I cannot put my finger on it (or perhaps foot). It is only sometimes and so catches you out even more. I think the problem is then that you push the pedal more (in blind panic) and this then when it catches up it leaps off. Sometimes there is no lag at all. I think it is something to do with a small gap on a roundabout. I think it senses it and the on board computer says we will have some fun here!!! It could be a german sense of humour??? I notice it most when I come off the motorway having been cruising quite fast and come to a complete halt before deciding I can go. But then need to get on with it (small gap etc). Around town hardly ever notice it.

By the way mine is a diesel sep 2005.

John