Won't change down a gear...

[TerrynJune]

Hi All

I've recently bought a 2008 E280CDi Estate. It's developed an issue that I can't sensibly get to the bottom of which I'm sure someone else must have experienced and, hopefully, cured.

Because of where I live I do quite a lot of careful, slow driving round country lanes. After a period slow driving, the car sometimes seems to quietly slip into some kind of limp home mode and won't change down a gear and seems to have no power until I stop and turn the engine off and on again. After that it's fine although the gearchange (especially moving down a gear) seems a little jerky.

I took it to our local garage who ran diagnostics on it but no codes showed up other than a message that there's a software update required that might cure a problem that sounded very similar even down to flagging up no diagnostic codes. I rang the specialist I bought it from who said it won't be that and said it'd be a sensor somewhere. The car then ran perfectly on a long motorway dash to see family and I had the chance to ask a local mechanic there. He flagged up the same issue that required a software update so I rang Mercedes and spoke to someone who sounded utterly disinterested who said they wouldn't know anything until it was on their STAR system and I'd have to pay for diagnostics (don't know how much) and "anything else they found". This didn't seem transparent enough for me and I was left feeling apprehensive about taking it to them.

Has anyone else experienced this problem and did it turn out to be a sensor or a software upgrade. If the latter, is it only Mercedes that can do this and roughly how much should I expect to pay?

All the best

 

[bob6600]

Software upgrades can be done by Indies who have access to an online STAR system.

Something does not sound right. If the car is going into limp mode then it should/would throw up a code.

Where are you based? Maybe we can recommend someone

 

[Lit91]

I think it's the stupid adaptation system which learns the way that you are driving the car. On your careful drive, the system makes the assumption that you want to continue in the same way and therefore will not kick down in the way that it would have done on a spirited drive.

Could be something else though...?

 

[milleplod]

I think it's the stupid adaptation system which learns the way that you are driving the car. On your careful drive, the system makes the assumption that you want to continue in the same way and therefore will not kick down in the way that it would have done on a spirited drive.

Could be something else though...?

Funny you should say that, but my R500 shows similar tendencies! If I've been pootling around like Miss Daisy for a while, usually close to home, I've noticed that reverting to 'normal' driving initially gives gearchanges that don't feel quite 'right', and the box doesn't feel that responsive. After a mile or so though, things feel normal again. I can't say mine's ever refused to change though.

Pete

 

[TerrynJune]

Hi All

Thanks for the replies. We're right in the middle of Devon if anyone has any local recommendations. I've since been very lucky that a friend of a friend up in Birmingham is a Mercedes dealer or Indie (I'm not sure which) and has offered to stick it on his STAR system to investigate it but I need to get it up there for that which I'll do as soon as I can get the time unless something else comes up in the meantime.

The changing down thing is really annoying and there doesn't seem a way out of it until you turn the ignition off and on again. When it does it, it's very frustrating as it's usually at the foot of a hill and when I put my foot down to get some acceleration, there's nothing. Yesterday it chose to do it crossing a lane of traffic so I want it fixed.

I've read about the adaptive system and wondered what the point in it is. Surely cars should just do what you tell them when you tell them to do it?!

I thought it was to do with DPF or the fact that I had a dead O2 sensor on the exhaust that might have been clicking it into limp home - it was running a bit rich but it doesn't have a DPF (phew!) and the new sensor's made no difference.

I appreciate all the help here though.

All the best

 

[Lit91]

What happens if you stick it into manual mode and try to change the gear up or down? If it doesn't change at all it sounds more like the electroplate/valvebody fault. £1K plus to repair and is a very common issue on 7G :/

 

[TerrynJune]

Touch wood, it's not that because the manual shift does seem to work and the revs change but it's like it limits power. I'm pretty sure that's the case. I've not had the car long so I'm still getting used to it. Despite a full service history, it's spent most of its time in a garage or off the road waiting to go into a garage. It's a lovely car when it works properly but by far and away the most troublesome, niggly car I've ever owned (and I had a Maestro once!)

 

[zipdip]

Well if it is the electroplate/valve body,it does not have to cost a £1000 you need a mechanic that knows Mercedes and so will be able to do the gearbox oil change correctly,and he could send the valve body to Bulgaria,I know seems off the wall,but they will repair your own valve body and send it back in a week,the cost is low,and because it is still your original part the car will run fine with it without a Star recode.when I get this move out of the way I will get my local mechanic to do just that and we will see,what you get for the money.