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 Marty Your Own Question

Marty
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 49762
Experience:  Bosch Certified Master Tech. Over 35 years experience.
13230946
Type Your Mercedes Question Here...
Marty is online now
A new question is answered every 9 seconds

Mercedes-Benz ml 63 amg: hi,my ml 63 amg when i accelerate

Resolved Question:

hi,my ml 63 amg when i accelerate i hear a rattle sound for couple seconds. my dealer has checked on computer no faults came up.he thinks not engine! to me sounds like the old pinking noise !!any ideas what it could be
Submitted: 2 years ago.
Category: Mercedes
Expert:  Marty replied 2 years ago.

eurotec :

Hi, as you can imagine, diagnosing a noise over the internet can be difficult. Having said that, one of the most common things that I find on the ML relating to a rattle on acceleration is a loose catalyst element inside the catalytic converter. When the catalyst breaks loose it will give you a rattle on acceleration. I'd have the converters checked for a loose catalyst element.

Customer:

thanks.rattle more noticeable when going up hill

eurotec :

I'd have to suspect the converter for something like this. It's a rather common problem on the ML.

eurotec :

I do not think that it's an engine ping. There are sensors on the motor that correct pinging.

Customer:

is this an expensive repair

eurotec :

Unfortunately it is. The converters are in the $800 - $1200 range but lately Mercedes has come out with remanufactured converters that are very reasonable. You'd have to have the dealer check availability if you need a converter.

Customer:

does my car have two of these having twin exhausts

eurotec :

Yes it does, one on each side.

Customer:

you deffinately dont think engine

eurotec :

Without hearing it it's hard to say but I doubt that it's an engine ping. I assume you use premium fuel. If you are using a lesser grade I'd switch to premium.

Customer:

i use normal unleaded 95, dealer said not 98 !

eurotec :

95 is fine, you're octane rating must be higher over there. Premium here is 93.

Customer:

ok so you think cat need replacing

eurotec :

I think that you should have them checked for a loose catalyst element.

Customer:

do they have to take exhausts off to check this

eurotec :

No, they use a rubber mallet to bang on the converter housing to see if it rattles.

Customer:

if no rattles their ok then ye. back to engine

eurotec :

Correct, but it would be most unusual to have a rattle from the engine.

Customer:

i hope your right, the engine still does have that "growl" when i accelerate, when im in low gear that rattle comes again

eurotec :

I do think that a loose catalyst element is the most likely cause. Without actually hearing it I cannot be sure but it's a pretty common complaint.

Customer:

ok thanks for your expert advice, ill have cats checked tomorow, hopefully your right and i finnaly get to bottom of this problem. maybe thats why dealer trying to fob me off with other maybe's !! last week he thought something might be loose so had eveything tightened up but still same noise!!

eurotec :

You're quite welcome. If you have any further questions you can always reply back to me even after you rate my service. Follow up questions are always available to you.

Customer:

last thing you deffinately dont think its misfiring

eurotec :

Definitely not, if it was misfiring the check engine light would come on and most likely the computer would shut down some cylinders and the car would run rough after the misfire occurred.

Customer:

ok great. i hope your right. just to clarify then, it only occurs when in low gears going up hill for example or i put my foot down to accelarate. still sounds like you said, loose elements in cat!

eurotec :

Yes that is correct, when the catalyst is loose it tends to rattle on acceleration.

Customer:

ok now you get paid !!!!many thanx

eurotec :

You're quite welcome :-)

Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 49762
Experience: Bosch Certified Master Tech. Over 35 years experience.
Marty and 5 other Mercedes Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • 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 Elm City, NC
< Last | Next >
  • 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 Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • 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 Walnut Creek, CA
  • 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 Charleston, WV
  • 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 Castleberry, FL
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
 
 
 

Meet The Experts:

 
 
 
  • MB Paul

    Mercedes Technician

    Satisfied Customers:

    3450
    Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes
< Last | Next >
  • http://ww2.justanswer.com/uploads/MB/MBpaul/2013-8-21_204936_paul.64x64.jpg MB Paul's Avatar

    MB Paul

    Mercedes Technician

    Satisfied Customers:

    3450
    Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    Mercedes Technician

    Satisfied Customers:

    22931
    Bosch Certified Master Tech. Over 35 years experience.
  • http://ww2.justanswer.com/uploads/RA/Racer76916/2012-5-8_6855_justanswerprofile.64x64.jpg Michael Warfield's Avatar

    Michael Warfield

    Factory Mercedes-Benz Technician

    Satisfied Customers:

    2807
    Mercedes-Benz Master Certified technician
  • http://ww2.justanswer.com/uploads/PE/peterpete190/2012-2-24_1274_20120215135406.64x64.jpg Pete's Avatar

    Pete

    Mercedes Mechanic

    Satisfied Customers:

    2556
    Over 15 years experience as a Mercedes dealer technician
  • http://ww2.justanswer.com/uploads/CA/caprio23/2011-12-13_155550_20111213105344.64x64.jpg Anthony's Avatar

    Anthony

    Mercedes Technician

    Satisfied Customers:

    642
    MB Tech. since 1997. ASE Master. MB Factory Technician. MB Antique Specialist.
  • http://ww2.justanswer.com/uploads/promerc/2009-01-04_220431_ja_pic.jpg promerc's Avatar

    promerc

    mercedes diagnostic technician

    Satisfied Customers:

    487
    Qualified mercedes diagnostic technician & service team manager , ATA registered Master tech
  • http://ww2.justanswer.com/uploads/73bbchevy/2009-12-8_232724_Picture_006.jpg Lou P. master tech's Avatar

    Lou P. master tech

    Mercedes Technician

    Satisfied Customers:

    418
    10 years master certified 100% fix rate knows mercedes like the back of my hand!!!!!