Mercedes

Have Mercedes questions? Ask a mechanic for answers ASAP

Ask an Expert,
Get an Answer ASAP!

ML320: , GFs 2002 ml320 with 140k has started idling rough…

Customer Question
Hi, GFs 2002 ml320 with...
Hi, GFs 2002 ml320 with 140k has started idling rough sometimes, better and worse, mainly in gear, got a few random misfire codes. Changed spark plugs which looked to be the original NKG "R" with the points on the electrodes burnt all the way down for the bosch 7422/FR8DPP33+ and it helped some but the problem is back, just doing some research.
plan to go over the vac system, clean maf and egr, check hoses including th eone by the fuel filter.
Submitted: 3 years ago.Category: Mercedes
Show More
Show Less
Ask Your Own Mercedes Question
Answered in 44 minutes by:
5/22/2015
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 3 years ago
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,895
Experience: 20 years Master Certified excellent fix rate and have access to factory wiring, and instructions.
Verified
Hello my name is ***** ***** i will do my best to help you , i strive for EXCELLENT service and nothing less. Our coil packs can cause slight misfires. So if a cylinder shows up on the scan tool for a misfire then swap The coil to a cylinder that is not misfiring and see if the code switched also the purge valve can stick open causing a rich condition , or pull the small vacuum line off of the fuel filter and see if fuel comes out. The pressure regulator is internal to the fuel filter and can internally leak causing a rough idle or Stalling condition. Those are all the most common. Also spray around the intake and air filter housing while the neck is connected and see if there are any air leaks. Oh and one more thing lol as if that wasn't enough the egr can stick open slightly causing rough idle and make sure the catalytic converters are solid and don't make noise when hit with a rubber mallet. Sometimes the internals come loose and clog the exhaust , there is not just one common issue as you can see but if you go through my list you will come up with a fix and also brake torque the engine and see how much the engine moved in drive and reverse , you could have s bad motor mount that makes the ML feel
Like it is misfiring. Hope this information helps Please take a second and click the box and rate my service GOOD OR EXCELLENT SERVICE if you feel I have been helpful and please request me in the future. If you feel I have not been helpful please DO NOT RATE BAD OR POOR AND WASTE YOUR MONEY , I will opt out to see if another expert can provide more or better assistance so you're not wasting your money!!. Thanks for choosing just answer. Lou. also , if you feel i deserve one , BONUSES are GREATLY APPRECIATED ! 😉
Ask Your Own Mercedes Question
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 3 years ago
I have taken my time to answer your question the best i could and i will continue to help if you need follow up information , all i ask is that you PLEASE take a second to rate my service so i may recieve my credit for assisting you. Thank you.
Ask Your Own Mercedes Question
Was this answer helpful?
Ask Lou P. master tech Your Own Question
Lou P. master tech
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,895
5,895 Satisfied Customers
Experience: 20 years Master Certified excellent fix rate and have access to factory wiring, and instructions.

Lou P. master tech is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

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 PElm 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.

PhilMarysville, 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.

CharlesWalnut 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!

SueCharleston, 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.

JimCastleberry, 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

< Previous | Next >

Meet the Experts:

MB Paul

MB Paul

Mercedes Technician

3,567 satisfied customers

Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes

Marty

Marty

Mercedes Technician

29,009 satisfied customers

Bosch Certified Master Tech. Over 35 years experience.

Lou P. master tech

Lou P. master tech

Mercedes Technician

5,895 satisfied customers

20 years Master Certified excellent fix rate and have access to factory wiring, and instructions.

Michael Warfield

Michael Warfield

Factory Mercedes-Benz Technician

3,131 satisfied customers

Mercedes-Benz Master Certified technician

Matt

Matt

Engineer

602 satisfied customers

Mechanical Engineer with 23 years experience in the auto industry, 8 yrs in formula 1 engine testing

promerc

promerc

mercedes diagnostic technician

553 satisfied customers

Qualified mercedes diagnostic technician & service team manager , ATA registered Master tech

Hipo64

Hipo64

Mercedes Technician

444 satisfied customers

Work and diagnose electronics on daily basis.

< Previous | Next >

Related Mercedes Questions
ML320 engine check flash after 20 minute driving , loss of
ML320 engine check flash after 20 minute driving , loss of power max 2500 rpm.… read more
autobahnauto
autobahnauto
diagnostician/shop owner
26 satisfied customers
Mercedes-Benz SL55 AMG I have just bought a 2004 sl55 amg
I have just bought a 2004 sl55 amg with 30,000 miles on the clock. I have done just over 3,000 miles and the dash keeps advising me to top up oil at next refuel every 1,000 miles I complete (in fact i… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Mercedes-Benz Sl 600: 2002 mbz sl600. 42,000 miles. Just
2002 mbz sl600. 42,000 miles. Just finished using sea foam to de-carb left side. Oil is still spraying out of dipstick (dipstick is forced out of tube) when i floor it. Replaced air pump check valve. … read more
Michael Warfield
Michael Warfield
Factory Mercedes-Benz Technician
Vocational, Technical or Trade Scho
3,131 satisfied customers
Changed out the Spark Plugs on my 1999 SL 500 AMG first the
Changed out the Spark Plugs on my 1999 SL 500 AMG first the left side. Car ran great. Next day the Right side, now the car Idles rough, Stalls and when you give it gas it bogs down no power … read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,895 satisfied customers
Random misfire from 1 2 3 and 4 changed all spark plugs and
random misfire from 1 2 3 and 4 changed all spark plugs and coils still same codes no injector pulse from those cylinders … read more
Wolfgang
Wolfgang
7 satisfied customers
Misfiring 0n sparks 5 and 6. Replaced spark plugs, wires,
Misfiring 0n sparks 5 and 6. Replaced spark plugs, wires, coils, and position sensor and still getting misfire … read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
91 satisfied customers
I just replaced my spark plug wires and after I replaced
I just replaced my spark plug wires and after I replaced them my car started with a rough idle and when I gave it gas it just dies it ran fine before I touched it … read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,895 satisfied customers
I was changing the spark plugs on a1999 c230,,and the wire
I was changing the spark plugs on a1999 c230,,and the wire connector that connects to the coil pack broke,,could I splice the wire and use another connector … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Costs to replace 8 spark plugs, clean all fuel injectors,
Costs to replace 8 spark plugs, clean all fuel injectors, replace left and right valve cover gaskets, replace tensioner on timing chain. … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
1985 SL380 cranks no start. Sl380. New spark plugs, wires,
yes, new spark plugs, wires, cap rotors, new fuel filter injectors, fuel pump, regulators, thermo time switch, modulator valve … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
1988 300e no power to coil. None. Pulling spark plugs.12
1988 300e no power to coil JA: Is the power loss consistent, or does it fluctuate? Customer: none JA: Are you fixing your 300E yourself? What have you tried so far? Customer: pulling spark plugs.12 te… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
Spark plug gap? Smart Passion 2014. Am ready to install new
yes, am ready to install new plugs but need to verify plug gap … read more
Kevin
Kevin
workshop foreman /master tech/mot tester
1 satisfied customers
What is the spark plug gap for a 79 450SL, I put in all new
I put in all new injectors and sleeves plus rebuilt the fuel distribution block and now it won't fire.… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
I recently replaced the spark plugs on my 2005 C230 Kompressor.
I recently replaced the spark plugs on my 2005 C230 Kompressor. I noticed that when i removed the old plugs, the treads on Cylinder 1 and 4 spark plugs were coated with oil, i did not notice whether t… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
Install new timing chain far as taking of parts and tools to use
what do i have to do to install new timing chain far as taking of parts and tools to use… read more
brownjeff
brownjeff
Associate Degree
13,873 satisfied customers
99 ML430: just started making a loud noise when the car is turned
99 ML430 just started making a loud noise when the car is turned on and the accelerators is pressed. It sounds like a truck.… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
mercedes ml320: I have a 1999 Mercedes ml320,it wont start
I have a 1999 Mercedes ml320,it wont start and when it does it stalls,i get a code p0300,cylinders 1 3 and 2 misfire… read more
Hipo64
Hipo64
Mercedes Technician
High School or GED
444 satisfied customers
1995 Mercedes S320: has a code p1170 (short term fuel trim..20 miles
My 1995 Mercedes S320 has a code P1170 (short term fuel trim) after driving about 20 miles. It is consistent everytime the code is cleared. Can you give me a hint where the problem could be? Thanks in… read more
nelson garcia
nelson garcia
auto mechanic
Vocational, Technical or Trade Scho
270 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x