Jumping out of GEAR

[ade1964]

I have a 2002 W203 C270CDI

Occasionally, while under Hard acceleration the gearbox jumps into a false neutral, there is no drive at all.

push into neutral, wait a couple of seconds, push back into drive and hey presto, works again.

Any ideas ?

 

[Dieselman]

Someone's had this, especially when cornering. Do a search.
First thoughts go to fluid and hydraulic plate in the gearbox. It sounds like the clutches might not be fully engaged so jump out under load.

 

[ade1964]

Had ATF changed, now though there are 2 problems, if it doesn't fliick into neutral, it sticks in 2nd gear and the tiptronic doesn't work.
Anyone ever get to the bottom of this?

 

[BlackC55]

Like Dieselman says. The electronic plate rings a bell for this fault.

 

[KLP 92]

Like Dieselman says. The electronic plate rings a bell for this fault.

Agree with the above.

Have the car put onto diagnostics and it should read P220A fault code, something along the lines of:

Code P220A the speed comparison from Y3/6n2 to Y3/6n3 is implausible (stored)

 

[KLP 92]

Had ATF changed, now though there are 2 problems, if it doesn't fliick into neutral, it sticks in 2nd gear and the tiptronic doesn't work.
Anyone ever get to the bottom of this?

Hopefully it will be the electronic plate, but it can also be the gearbox slipping which would bring up the same fault codes and would explain why the ATF change made it worse.

I had exactly the same probs on a C270 2002 model which resulted in a replacement gearbox.

 

[panason1c]

As previously mentioned, the electro-hydraulic plate could be the cause....apparently, small metal shavings can settle on the plate and cause 'electronic gremlins' ...resulting in false neutrals, etc......the cure is to remove the plate (a fairly easy tranny 'in-situ' job) and thoroughly wash it, then refit it, then....fingers crossed. (-:

 

[ade1964]

Thank you to everyone for the advice, going back today for check, will let you know what it was.

 

[clk230komp]

Really great comments. I can identify some of the problems as welll and am trying to get to the bottom of this as well. My mechanic sasy I need a new autobox for my w208.

 

[ade1964]

Think my problem is finally sorted, as it only happened on corners, someone suggested I turn off the traction control.
Ran for a week with no problems whatsoever, Independant garage seems to think its a sensor inside the box, which is linked to Traction control system.
Being done as I write, only thing is, its taking 3-4 days to complete as its "deep" inside box itself, and requires a complete strip down.

Will keep you informed if works

 

[KLP 92]

Think my problem is finally sorted, as it only happened on corners, someone suggested I turn off the traction control.
Ran for a week with no problems whatsoever, Independant garage seems to think its a sensor inside the box, which is linked to Traction control system.
Being done as I write, only thing is, its taking 3-4 days to complete as its "deep" inside box itself, and requires a complete strip down.

Will keep you informed if works

It only takes a day to rebuild a box! The sensors are accessable in 1-2 hours labour. I think someones having a laugh if its taking 3 days to fix it.

 

[1998K]

mmh since it's my first automatic transmission I'm quite worried due to several problems I hear around about automatic transmission on 270cdi!

Hope these problems will not happen

 

[ade1964]

Got the car back, 1 week in total, they road tested it, upon receipt of car, I managed a whole 10 mile before stuck in 2nd gear again. No corners and no hard acceleration.

Back to Independant dealer, diagnostic showing different errors. Left it there, hopefully hear something tomorrow.

Does anybody know of any reason why/when the tiptronic should be used, I have been told I could possibly be selecting the gears incorrectly, sounds like twaddle to me.

 

[fredfloggle]

Got the car back, 1 week in total, they road tested it, upon receipt of car, I managed a whole 10 mile before stuck in 2nd gear again. No corners and no hard acceleration.

Back to Independant dealer, diagnostic showing different errors. Left it there, hopefully hear something tomorrow.

Does anybody know of any reason why/when the tiptronic should be used, I have been told I could possibly be selecting the gears incorrectly, sounds like twaddle to me.

nope , if you force a low gear a boot it , it will hold on to the gears up to the limit - not that . Give it some clog ,and see if it changes up , if not , hold the stick to the right , if not , drive it back through his showroom window .

 

[ade1964]

Car GONE

Finally succumbed, the garage gave me my money back, not going back to a mercedes - EVER.
Might try Bmw/Audi/Jaguar

 

[BlackC55]

Finally succumbed, the garage gave me my money back, not going back to a mercedes - EVER.
Might try Bmw/Audi/Jaguar

The problem is fixable I assure you.

I suspect the valve body is the problem.

But you have got rid of the car now

Not all MB's are bad. We just here of the bad ones.

 

[davidatgb]

Variation on this theme

I would appreciate anyone else's experience on this slight variation to the problem in this thread.

I recently bought a second hand 2003 C270 CDI auto and the auto box also has this problem of racing between gear changes. It happens under acceleration and only when the engine is hot. It has twice jumped out of gear completely, but what usually happens is that the engine accelerates to around 3000 rpm and changes gear, but it "misses" and revs up by about 500 rpm before changing into the higher gear and dropping back to where it should be in the higher gear.

I had the gearbox and torque converter completely drained (all 7.5 litres) and the filter replaced under the dealer warranty, and this definitely helped. However, the problem did not go away completely.

It then turned out that the car had been "chipped" at some time in the past. There is a small black box that bypasses the cable that normally connects to to the front of the common rail, so the original cable that Mercedes fitted connects to the chip box, and the chip box then connects to the common rail.

Two things happened as a result of removing this chip box. (1) the power and fuel consumption returned to Mercedes claimed levels, and (2) the gearbox issue reduced by upwards of 90% and now only races occasionally, if at all.

I'm drawn to the conclusion that the chip is making an existing slight problem (probably the speed sensor on the gearbox control plate) considerably worse. The engine is also a lot smoother and quieter now without the chip. So this chip stays out, despite my MPG dropping on a run from 61mpg to 53mpg.

I have no idea what brand the chip is as there are no labels, but I suspect a cheap-and-nasty. Has anyone ever found a chip that does not create problems or make existing ones worse? I did like the 61MPG!