604benz

Hi Guys in the last week I have had my transmission play up twice, the car runs fine and transmission shifts smoothly and then I get to a stop light and put my foot on the accelerator and car just moves really slowly and engine revs high.
I called my indy tech and he told me to turn off car and restart and it runs fine, he said it was probably an electrical issue, any ideas before I drop it off for diagnose.

Philip317

Get your mechanic to check whether transmission oil has contaminated your ECU.
MB has had problems in this area where transmission leaks from the transmission unit through a bushing and ' climbs ' the cable leading to the ECU and then contaminates the unit with the result that the transmission acts erratically. This problem in other models of MB is known to MB so my advice to you is to firstly get the transmission checked by an independent mechanic rather than an MB mechanic because MB have been trying to conceal this problem along with other problems with transmissions such as when the transmission is put under pressure through acceleration it can sometime 'lock' into a false neutral being ' a no gear' Scenario and then there is a complete loss of power. I am afraid that MB are well aware of these problems. Such cars should not be on the road as they cab be death traps especially if you are expecting that surge of power at such a crucial moment and then find it ain't there. Take care

604benz

Thanks for the info Philip, I got the car diagnosed and it seems the valve body and speed sensor are failing, dealership will not sell this part to my indy tech, they say only dealership is authorised to do repair, what a rip off they want $2200 plus 4 hours labour.
My torque converter has been making a whining noise for the last year as well, so I will just drive it until it completely fails and by a refurbished transmission from Sun Valley Mercedes Transmissions for $3500 plus freight which includes transmission, torque converter and valve body with 2 year warranty.
This is their link for anyone in similar situation

http://www.mercedesdismantlers.com/M...ice%20List.htm

Em Bee Lover

Wow. That's a lot of money. I felt ripped when my USA MB dlr. snagged me for over $1100. What torqued me, if you'll allow the word play, is the part cost was $250. Plus, it was a remanufactured MB part....not even "new". They said $500 was pulling and replacing the transmission fluid.

Tell me again why we drive these POS?

BallaFL

I had a similar problem with my 550. Ended up replacing the whole transmission. Call MB USA and complain. They helped me out 2yrs outside of warranty.

AMG55TECH

This issue of oil contaminating the ECU was only an issue on the 722.6 transmission. The transmission on a W221 is a 722.9 transmission. The ETC is actually internal to the transmission and doesnt cause many issues at all any more. But unfortunatly the turbine speed sensor seems to be junk. Also as a side note... When the 722.9 transmission was introduced, MB stated that it was a non-serviceable transmission and fluid never needed to be changed. Later, MB recommended/ required a fluid and filter change ONCE at 39,000 miles. And now on some models MB recommends/ requires a fluid and filter change EVERY 40,000 miles. GUYS...do your self a favor and change the fluid and filter!! dont wait until the tranny craps out.

brianw430

My transmission acted up much like yours when I first got it at 64,000 or so, don't recall exact mileage. Did the, turn it off and restart thing, and that worked temporarily. At my first opportunity, I had the tranny fluid FLUSHED and replaced as well as the filter. Make sure they flush it, as the service advisor told me that was not possible. I insisted and he asked a tech and he confirmed yes it can be done, and they have a make-shift fitting to complete the job. And this is a certified MB dealer! They did not have a part to properly flush the tranny and converter!

Since the fluid flush and filter replacement I have had zero issues...~20,000 miles. Yes, I'm knocking on wood!

I hope this works out for you!