eran48
Member Since: 10 Dec 2007
Location: Sydney
Posts: 165
  
|
| I managed to stall the auto D3 twice off road |
|
G'day everybody,
Had a rather interesting experience on Saturday during one of the RR club trips.
I was playing on this steepish slope (about 45 - 50 degrees but felt like 90  ) and was testing to see if I can slowly crawl up without any momentum. At the steepest bit, the vehicle stopped moving but with all 4 wheels still slowly spinning.
I eased off on the accelarator pedal and the car started reversing down the slope. The engine stalled almost immediately. I had not moved the gearbox out of Drive to Reverse.
I had never stalled an automatic before and had another go up the slope and managed to stall the engine again.
Tried it a third time, this time with Revese engaged and all was fine.
Is it normal for the engine to stall like this? I realise that the situation is a bit extreme with my forcing the car to go backwards while the gearbox is in Drive. But this shouldn't stall the engine, should it?
Regards.
|
 30th Jun 2008 7:00 am |
|
|
Ken
Member Since: 20 Feb 2006
Location: Here
Posts: 10865
|
Mines done it a couple of times always on a cold engine in low box
|
| 30th Jun 2008 7:24 am |
|
|
AndrewS
Tarquin of the Desert
Member Since: 06 May 2005
Location: Y...... because I can
Posts: 10442
|
Mine did it all the fooking time when 4x4ing up steep things  Then it started to change gear erratically during normal driving. Took it to the dealer they cleared some faults in the gearbox and now its OK  In the Beginning there was nothing, which exploded.
|
| 30th Jun 2008 8:03 am |
|
|
Neil Pettersen
Member Since: 23 Nov 2007
Location: Cutting the grass
Posts: 1254
|
| Re: I managed to stall the auto D3 twice off road |
|
eran48 wrote:.... this shouldn't stall the engine, should it?
Many automatics will stall if you roll backwards while in drive.
I've done it in a few rentals on steep hills while looking at houses for sale.
|
| 30th Jun 2008 8:35 am |
|
|
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
|
| Re: I managed to stall the auto D3 twice off road |
|
eran48 wrote:I had never stalled an automatic before and had another go up the slope and managed to stall the engine again.
the lockup in the torque converter (according to the literature) bringes the auto box very close to the function of a manual box. it will stall every time while in low box.
|
| 30th Jun 2008 8:44 am |
|
|
eran48
Member Since: 10 Dec 2007
Location: Sydney
Posts: 165
|
catweasel - that was my suspicion. The car would roll back a bit until the torque converter locks and that's when the engine stalls. It actually happens quite abruptly.
So the gear box is not as intelligent as it should be? Perhaps it should know that when the vehicle is rolling backwards while in Drive and with no pressure on the accelarator pedal, then it should not lock the torque converter.
Cheers
|
| 1st Jul 2008 5:20 am |
|
|
hernan1304
Member Since: 28 Feb 2008
Location: Dubai
Posts: 490
  
|
When going uphill offroad:
1) get some momentum going
2) stay on the accelerator
3) if you fail to make the climb, come back down IN REVERSE
4) do not attempt to U-turn
Basic rules that apply to manual and auto alike.
Although I agree it's surprising that LR doesn't have a safety override for this, there should in fact be no "real world" situation where you are off the brakes, off the accelerator, and in Drive on a very steep incline.
Stay safe!
|
| 3rd Jul 2008 5:47 am |
|
|
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
|
theres only so much the car can do, it does require some competence on the drivers part 
and being in D with no input to the pedals holds the car in place nicely
|
| 3rd Jul 2008 7:26 am |
|
|
hernan1304
Member Since: 28 Feb 2008
Location: Dubai
Posts: 490
|
Isn't there a "double-braking" thing that you can do to hold the car on hills? I think I remember reading a post about this not too long ago.
|
| 3rd Jul 2008 8:44 am |
|
|
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
|
urban legend I think from memory
|
| 3rd Jul 2008 11:19 am |
|
|
eran48
Member Since: 10 Dec 2007
Location: Sydney
Posts: 165
|
I don't disagree that it is certainly preferable to have some familiarity with the Disco3 AND off-roading techniques before venturing out to the harder off road bits.
If the vehicle is on a steep enough slope, and the driver lifts off the accelarator pedal when in Drive, the car will actual start rolling backwards down the slope. The auto box will only hold the car on milder slopes and not on steeper ones. When this happens and the torque converter locks up, that's when the engine stalls.
I guess we just need to remember, when stopping on a steep slope, to hit the brakes and select Reverse before allowing the car to reverse down.
I seem to remember that with the Td5, I can actually allow the car to roll back down while in Drive without stalling the engine. But I could be wrong here
Cheers
|
| 4th Jul 2008 8:13 am |
|
|
Sniegy
Member Since: 01 May 2006
Location: Melbourne
Posts: 72
 
|
Evening all,
Manually select 3rd gear & see how it goes.
I had also noted this when i first drove a D3 offroad, i tried 3rd Manual & then did the same hill with no problems.
It is also good to have a little throttle going. D4 Alaska/Almond 2.7 TDV6 with E-diff & extra's.. 
Keep smilin' Pete.
|
| 5th Jul 2008 1:04 pm |
|
|
dick dastardly
Member Since: 29 May 2007
Location: wiggleigh bottom
Posts: 1112
 
|
Sniegy wrote:Evening all,
Manually select 3rd gear & see how it goes.
I had also noted this when i first drove a D3 offroad, i tried 3rd Manual & then did the same hill with no problems.
It is also good to have a little throttle going.
And DSC off - as you know, but it does like coming back on again There's one wheel on my wagon, but i'm still rollin' along, it's the cherokee, they're after me, but I'm singing a happy song
|
| 5th Jul 2008 10:09 pm |
|
|
10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
|
It's reverse torque through the transmission - with a 'normal' auto this wouldn't happen, the D3 has an electronically controlled auto box which will keep the TC locked up as long as possible to maintain engine braking, keeping the revs at 950-1000 will prevent this, altenatively, get a manual 'box and learn to drive properly 
|
| 5th Jul 2008 11:24 pm |
|
|
catweasel
Member Since: 05 May 2006
Location: Bundaleer
Posts: 4805
|
Philistine
|
| 6th Jul 2008 1:59 am |
|
|
