How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask MB Paul Your Own Question

MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
15777119
Type Your Mercedes Question Here...
MB Paul is online now

I have an ML270 2005. Ongoing transmission problem. Over revs

Resolved Question:

I have an ML270 2005. Ongoing transmission problem. Over revs when changing 3 to 4 gear. I know the box leaks, I think the oil level is ok.
After a long drive towing a relatively light caravan to Cornwall, I lost drive on a couple of occasions. Got worse the last 30 miles of the trip.
In limp mode now. Worried about getting home next Sat.
I would welcome your advice.
Thank you.
Dave
Submitted: 2 years ago.
Category: Mercedes
Expert:  MB Paul replied 2 years ago.
Hi Dave,

In the first instance I would always recommend having the car checked on Mercedes STAR diagnostic tool to see what codes are stored in the transmission control unit.

If you are sure that the transmission oil level is correct (which a special workshop dipstick is required to confirm) then the next step will be to process the codes stored.

There are many possibilities but often the fault is down to faults with the sensors on the electrical plate inside the transmission or the transmission is slipping due to internal wear. The fact that you say the engine over revs when changing gear leads me to think that this is the most likely cause & often shows up more when towing.

If the transmission is slipping then there will be fault codes stored indicating that it has detected slip or implausible transmission ratios.

If it is slipping then you could try having the transmission flushed with an oil & filter change but in all reality it could very well need a replacement transmission or a rebuild of your unit. Obviously this is very costly.

In summary a definate check for correct oil level is recommended first, followed by a check for fault codes with a diagnostic tool & then processing these codes to determine the exact means of repair.

There are of course many other possibilities & I am advising you of the steps based on information you have given.

Best regards, Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience: Mercedes Benz Qualified Diagnostic Technician
MB Paul and other Mercedes Specialists are ready to help you

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Matt

    Matt

    Mechanical Engineer

    Satisfied Customers:

    484
    BEng hons Mech engineering, in auto industry 22 years
< Previous | Next >
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    484
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    21378
    Bosch Certified Master Technician with over 35 years experience in the automotive industry.
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG mike_a_mechanic's Avatar

    mike_a_mechanic

    Mercedes Mechanic

    Satisfied Customers:

    116
    17 years experience as a auto mechanic, foreign and domestic.5 years running my own repair business.
  • http://ww2.justanswer.com/uploads/MB/MBpaul/2013-8-21_204936_paul.64x64.jpg MB Paul's Avatar

    MB Paul

    Mercedes Technician

    Satisfied Customers:

    212
    Mercedes Benz Qualified Diagnostic Technician
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1081
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    453
    Licensed diagnostic and repair technician