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 Mike Your Own Question

Mike
Mike, UK Car Mechanic
Category: UK Car
Satisfied Customers: 38842
Experience:  Hi, I am a Car/ vehicle technician of 34 years. 29of -running my own repair/diagnostic business.
9261905
Type Your UK Car Question Here...
Mike is online now
A new question is answered every 9 seconds

mercedes benz c 270 cdi I have a mb 270 cdi diesel,auto, 2002.

Resolved Question:

I have a mb 270 cdi diesel,auto, 2002. I used to have terrific accelleration but now at around 50-70 if I press the throttle pedal down I will increase speed slowly and can press the pedal to the floor which makes no difference. I could never press the pedal to the floor before as the car would take off after dropping a gear. My on board computer relays my fuel consumpion is better and the car drives fine, I just miss the accelleration at times on the motorway. The engine surges and hunts which is probably more annoying than the accelleration. The car has been like this for months and is not a major problem but before I used to move the throttle an inch and get results. Now I have to wait till the car picks up speed in its own time. Is this an injector problem. It happened suddenly, not gradually. I have gripped the turbo hose to the engine and it swells up as I rev the engine suggesting the turbo is fine.
Submitted: 3 years ago.
Category: UK Car
Expert:  Mike replied 3 years ago.
Hello and Welcome to justanswer..

What is the mileage you have on the vehicle?

What is its service / recent repair history?

Do you have any warning lights on the dash at all?

Can you feel the turbo come in at around 1800 rpm when driving - can you test for that and let me know...?

Lastly - when you get this problem - lack of power at that range -does it blow smoke..and if so ,what colour?

Rgds - MIKE............................................
Customer: replied 3 years ago.

hi mike, sorry for the delay. my car has covered 123750 miles, serviced regularly and about 18 months ago the epc light came on and engine derated when I tried to accelerate. switching the ignition off cleared the malfunction, but I had to be careful not to accelerate too quickly. This was no. 1 injector which was replaced and fault cleared.

There are no warning lights on and the black smoke I used to get seems to hav e reduced when I accellerate. I did discover something important yesterday. I wanted to check how much smoke was coming from exhaust and when revving the engine to maximum it would only rev to 3000 rpm instead of 5000rpm. The revs cut out at 3000rpm leaving the maximum throttle travel dead.. the turbo appears fine. When I first bought the car It passed the smoke test with 1 rev of the engine as the reading was so low but the last 2 mot's I have to clear the exhaust by revving the engine to get the readings down. The car does 80 mph @2500 rpm and would explain why the accelleration is poor when I put the pedal to the floor as that end of the travel is dead.

Hope this has narrowed down the area of problem.

 

Thanks, Sandy

Expert:  Mike replied 3 years ago.
Hello again - thank you for your reply.. thats fine.. and the info too which is very helpful..

There are a couple of different things that can be causing what you have here..

Given all that you have described, the air flow meter comes to mind straight away..as a common cause of such problems...

Yes, you could have injector trouble - but its just as likely to be the MAF ( air meter )

You can try disconnecting that and see if that improves / cures it - take the electric connector off - the engine may run badly on idle etc - but if things are better power wise, its a good indication of the Maf being faulty. ( This is the unit in the large air tubing from the air filter )

If its not that - then I have to recommend have a plug in diagnostic test done. This will check for fault codes if it has any -and if not - it can check the live readings as the car is driven - hence any faults will become apparent "on screen".

MOst small garages have the equipment to do these tests for you so you dont need to use a dealer.. Certainly as there are several other things it could be - if its not the Maf.., it makes sense to do that because that will find the fault rather than replacing items which gets very expensive and is a waste of time and money.

So try that with the Maf first..If that cures it - great. If not - have the diagnostics done.. that is the best , quickest and most cost effective way forward on this one for you ..

I'm very pleased to have helped you - but do ask me if you need anything more..


Kind Rgds, MIKE

 

  • >>>>>>>>>Please don't forget ....Please press the ACCEPT button if you are happy with my answer/advice given - as that's how I get paid for my time, knowledge and expertise given. Thank you.

Feedback and any Bonuses are always appreciated too. Thank you.

Mike, UK Car Mechanic
Category: UK Car
Satisfied Customers: 38842
Experience: Hi, I am a Car/ vehicle technician of 34 years. 29of -running my own repair/diagnostic business.
Mike and 5 other UK Car 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:

 
 
 
  • 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
< Last | Next >
  • 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
  • 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 Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Marty

    European Car Expert

    Satisfied Customers:

    349
    ASE & Bosch Certified Master Tech. Over 30 years experience.
< Last | Next >
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    European Car Expert

    Satisfied Customers:

    349
    ASE & Bosch Certified Master Tech. Over 30 years experience.
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Shop Owner

    Satisfied Customers:

    1040
    17 years Shop Owner /Technician. 27 years experience,
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    UK Car Mechanic

    Satisfied Customers:

    472
    12 years as a technician at a Ford and Jaguar dealer Ford and Jaguar factory certified
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    4034
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/NA/nabilc/2011-1-24_205715_jap500.64x64.jpg Billy's Avatar

    Billy

    Trainer/Master tech.

    Satisfied Customers:

    1276
    Trainer - master tech., SAE member
  • http://ww2.justanswer.com/uploads/witt0018/2009-02-09_180738_trev2.jpg Trevor Witting's Avatar

    Trevor Witting

    UK Car Mechanic

    Satisfied Customers:

    815
    NVQ 3, Modern Apprenticeship, MOT Tester, 15+ years experience diagnostic technician
  • http://ww2.justanswer.com/uploads/RO/RobMechanic/068.64x64.JPG Rob's Avatar

    Rob

    UK Car Mechanic

    Satisfied Customers:

    811
    city and guilds level 1 2and 3. mot tester , 28 years experience set up training college in afghanistan