E320 Gearbox Issues - No Kick Down???

[Beardz]

Coming back from holiday fully loaded on dual carriageway, went to overtake truck, planted foot into carpet and got a nasty shock!! Engine lurched (thought it was going to conk out), took foot off pedal all calmed down but completely lost any kick down from the box. Was ok going up & down the box in tip but not in drive?

Pulled in turned engine off, left it for a few seconds and all seems to be well again (although i didn't dare put it under too much load in case it did it again). Any ideas?

Mechanical box problem or electrical/software issue (it was absolutely hammering it with rain at the time)?

Your advice would be appreciated.

 

[lynall]

First thing is always get the oil level checked then go from there.




Lynall

 

[Beardz]

A friend has suggested that the lack of kickdown was because the car went in limp home mode?

No warning/error messages displayed on the dash.

I suppose I will have to bite the bullet and get the car looked at by someone with MB diagnostic kit. I presume there will be at least an error message on the ecu?

 

[st4]

yep star will show something but a gearbox oil leak would surely be accompanied by a lack of oil. when the car is parked up is there any oil on the drive, is there any oil around the gearbox area underneath the car. Usually with lack of gearbox oil changes may not happen really at all, or very reluctantly.

Would a MAF problem cause limp home (and the subsequent loss of power-restricted RPM prevents peak power production) experienced

 

[Dieselman]

The MAF would normally cause it to kick down and the engine to go to high revs but with no power.
This could be gearbox or engine related, maybe something like boost pressure.
Have the codes read.

 

[Vlad]

Had a very similar situation in an entirely different model, ie a S500.....no kickdown but still worked perfectly well on the Tiptronic. After switching off the engine and restarting kickdown on the gearbox worked perfectly....turned out to be a failing MAF.

 

[BlackC55]

You basicaly have a lack of power issue. Many things can cause it. Get the fault codes read and post back.

 

[Beardz]

Hope to get codes read at the weekend, hasn't done it again since so trusting it is not something that will result in a major breakdown in the meantime.

No oil puddles in the garage so again assuming everything is ok there (not sure when the oil was last replaced though.

How long does it last? The car has just clocked up 100k.

I note that another member posting is having exactly the same trouble with their C320 CDi. I assume that it has the same V6 lump under the bonnet and could therefore suffering from the same issues (i.e MAF failure).

If this is the case what roughly am i looking at costwise?

I'll use an independant rather than stealership (my local will barely give me the time of day).

 

[SLKrazy]

Take MAF off and check it for Oil cont5amination. Try not to touch it with your fingers and if it is Oily then get some electrical cintact cleaner spray and spray a little onto the plastic to check for a reaction. If there is no reaction after 20sec then spray liberally onto the sensor and all around the housing. Let it evaporate and clean the residue with paper towels or lint free cloth but do not go near the sensor as this will be clean. Just wipe the big areas you can reach easily.
This has worked on the couple of occassions when I experienced similar symtom and it works a treat.
Not sure where to buy electrosolve on the high street but if you have access to RS Components or Screwfix or defo Maplins however they are usually expensive.
Hope this helps

 

[SLKrazy]

sorry, contact cleaner and contamination spelling error

 

[Beardz]

Car has been in for diagnostic only 2 faults appeared.

1. Turbo throttle valve sensor (i can't remember the exact name of it)???

2. Build up gases within the exhaust pipes

A test was run on fault no:1 and everything seemed to work ok.

No test was carried out for no: 2.

My local merc specialist cleared down both the faults and advised that i get in touch if it happens again and put it on the diagnostic again to see if same faults are flagged.

I have to say so far so good.

If it is either of the above then i could be looking at a new turbo or new cats for the exhausts (V6 diesel).

Both sound expensive fixes.

Has anyone had similar probs?

 

[madmerc1]

I had similar problem - car drove faultlessley except when accelerator pedal pressed to the fully down (kickdown) position. This was caused by the throttle position sensor.