Rolling backwards!

[team_express]

We've got a couple of 2005 E320CDi (W211?) cars here and one rolls backwards when in drive and the gearbox is set to sport. When sport isn't selected, it holds on an incline and doesn't roll back. Our local dealer has it today and said this was normal. We've checked the other at that's the same.

Our previous E320 petrols that we still have don't roll back at all, ever.

Has anyone got any ideas or reasons behind this oddity?

 

[jberks]

Its generally related to idle speed and the incline involved. I've found that my E240 rolls back if the incline is steep enough which surprised me as my previous Mercs didn't, though I drove a jag a while back and that rolled virtually on the flat!

I would expect it to be more likely to roll in W setting than S, as W is softer and hence should allow more torque converter slip.

All very confusing.
Do both your 320's do it or just one?

 

[team_express]

Yep. The dealer rang this morning about the one they've got to look at and said that it will slip in S, so we tried the other here and that did it too.

In the meantime, we've spoken to an independent, and they said that all of the new ones do it, so it looks like we'll have to learn to engage neutral and apply the brake (if we remember how).

 

[pascal]

Team,
I suppose you mean when driving stop/start up an incline, and not stopped.
Why put it into neutral. Why not just put your foot on the brake in drive?

If you mean stopped, and in drive? Why? Surely it should be in 'P' and handbrake engagaged, as with all autos.

 

[jberks]

You don't need to put it in neutral when the handbrake is on, just leave it in drive. Apparently its better to leave it alone than knock it in and out of neutral.

 

[stwat]

Just put your right foot on the brake and release when you give it some gas.

Stu

 

[Rory]

Maybe this is gear related? Doesn't it select 1st gear in Sport mode, but 2nd otherwise?

 

[piestore]

722.6 box

Hi
To try and clear up some confusion the mode switch S/W on older cars and S/C on the new E class refers to summer or winter/cold when in W or C it starts in second gear given certian factors and it also changes the shift pattern this is generaly only for slippery conditions. The slipping back on a hill is normal with an electronic box and if W or C is selected it will hold this is normal.

As for the E class 211 to make hill starts very easy the SBC braking system has a hold function built in, after coming to a halt if further pressure is applied to the pedal the SBC HOLD function is activated and displayed in the cluster the moment the gas pedal is pressed SBC hold is canceled

 

[Ger D]

You don't need to put it in neutral when the handbrake is on, just leave it in drive. Apparently its better to leave it alone than knock it in and out of neutral.

Hi Jberks, this is interesting. I expect like me many drivers slip it in and out of neutral.
Are you completely sure about this and have you any other useful driving style tips?

Thanks in advance

 

[jberks]

I don't claim to be an expert, but I am told that you put more wear on the box by switching in and out of gear, than by simply holding it against the torque converter which is designed to slip. In any case, unless there is a positive benefit of dropping it into neutral when stationary there is little point doing it. The problems people get with autos tend to be on the gear change side rather than a worn torque converter. Then again the auto box is a bit of a mechanical mystery to me but I'm sure someone will confirm this or shout me down!

 

[pascal]

Interesting

That SBC hold funtion. There was someone posting last week about it. They were driving the car for ages and did not know how to activate it. Part of some comfort driving system, is how it was described.

A question for Piestore: Does the SBC hold funtion do any more than just hold the brakes, ie put the box in neutral.

Regards putting the car in neutral while stopped in traffic going up a hill.
I would never. The only time my car, or any other auto I drove, goes to 'N' is on its way from 'D' to 'R' or vicversa.