W211 E270 cdi - intermitant jerk with gear change

[Mercgaz]

Hi all,

I have had a problem for quite a while now, the car seems to jolt/jerk when changing into 2nd to 3rd gear. The car also seems to grumble when doing this .....the revs also sometimes surge while driving at a steady speed - not much maybe 100rpm.

The above only happens every now and then but often hot or cold.

The other problem is when going down steep hill the the car jolts quite nasty feeling.

I know about the valeo problem but I really do think it is that..due to milles and age would have happened to previous owners...besides do not think the problems are as serious as the associated problems with valeo.

I had major service and gearbox service last year.

Any help would be appreciated..

 

[mersum1es]

Check box oil level. Check transmission ECU box not holding oil. Fault codes would tell if there are some troubles with tranny mechanical parts (TC lock valve, speed sensors etc.)

 

[Mercgaz]

Thank you, as I say it does not happen all time....

It almost ferls as if it changes gear to quickly before the revs have chance to build up, but is betwee.n 2nd to 3rd gear.


That aside in general what would cause the revs to surge slightly when driving?

 

[Mercgaz]

Been on star and no faults...

 

[BlackC55]

Get the aft tested for glycol.

 

[Mercgaz]

I did suggest that to the indie, he said he is sure if it is that would have happened before now and likely to have been rectified...

The car is ten years old in september

 

[Mercgaz]

It is running better sine a new battery and reset by star...this does not happen every time only every now and then....

 

[Leec320]

Jerky 7 G gearboxes

Am new to Mercs after various reasonable cars in the past, am i expecting too much of the 7G, is it ever a seamless gear change? Mine can be nice and smooth on one journey, then jerky on both up and downshift. Been reading various posts on the subject and am not sure any more. My c320 cdi (58 plate) has been back to the dealer a few times, had all new software, oil level checks and have been told there is nothing wrong with it. Can anyone give me some ammo to take to the dealer so i can challenge them. Or do i just accept that the engine is great and the gearbox is from the 1970's????