7g gearbox

[Goingmad]

Ok guys I have a 2014 Mercedes E220 se cdi w212 saloon. When first starting and driving after the car has sat all night my gearbox plays up it will not know what gear it is in and the display on my dash goes blank to explain when driving the dash says for example D2 for second gear when this fault happens it’s just says D and the car dips and won’t accelerate only happens once a day at the moment but when it does you can’t accelerate and the car breaks. Can anyone help please.

 

[Mike Smith]

You need to the diagnostics done, it could be anything from a failing battery to an ecu.

 

[alexanderfoti]

I suspect you have the initial symptoms of a failing speed sensor.

Normally they fail after a long run, but a quick diag will be able to give an indiation.

Does it go back into gear by itself, or does it need an ignition reset?

 

[Goingmad]

It goes back into gear itself like I say no warnings come up and only does it when it’s cold once it warms up it behaves so to speak. But sometimes when it’s warm it feels like the gear changes ain’t as smooth as they should be

 

[alexanderfoti]

It goes back into gear itself like I say no warnings come up and only does it when it’s cold once it warms up it behaves so to speak. But sometimes when it’s warm it feels like the gear changes ain’t as smooth as they should be

I would check the gerarbox oil level first, bit difficult on the 7g but not impossible.

If OK, then read the codes from the gearbox module and engine ECU to make an informed decision as to the root cause.

 

[Goingmad]

I have a leak from this unit here? Is this anything to do with my gearbox

 

[alexanderfoti]

I have a leak from this unit here? Is this anything to do with my gearbox

Where is that picture, down the side of the airbox?

*nvm* down the front of the engine where the crank pulley is.

 

[alexanderfoti]

No idea, there is definitely a leak there, need to track the source, its unlikely though as thats the front of the engine and leaks normally go backwards.

 

[Goingmad]

Where is that picture, down the side of the airbox?

*nvm* down the front of the engine where the crank pulley is.

That’s at the front where the crank pulley is

 

[Goingmad]

No idea, there is definitely a leak there, need to track the source, its unlikely though as thats the front of the engine and leaks normally go backwards.

Seems to leak up from the metal pipes that goes into it

 

[alexanderfoti]

Ah in that case. The gearbox oil cooler or its pipes are leaking, and your level will be low.

 

[Goingmad]

So will it be best to replace that unit or can I just re tighten the nuts and replace gearbox oil.

 

[Mike Smith]

There may be rubber O rings that can be replaced.

 

[alexanderfoti]

So will it be best to replace that unit or can I just re tighten the nuts and replace gearbox oil.

You need to check if the lines leaking/track down the leak. Clean up the joints and take it from there. The coolers are quite common to leak themselves though, so dont rule that out.

Gearbox oil needs to be pumped in from underneath on the 7g at a specific trans temp.

 

[Goingmad]

Ok quick update the cooler is leaking nuts aren’t loose so I will be replacing the cooling unit and refilling the gearbox