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 Matt Your Own Question

Matt
Matt, Mechanical Engineer
Category: Ford
Satisfied Customers: 21113
Experience:  BEng hons Mech engineering, in auto industry 22 years
12772297
Type Your Ford Question Here...
Matt is online now

Car: Ford Fiesta 3 door Hatch batch 1.1 L reg: My engine

Resolved Question:

Car: Ford Fiesta 3 door Hatch batch 1.1 L reg:

My engine warning light has come on and stays on all the time while I am driving. The engine appears to be labouring and when the car is stationery the engine sounds 'lumpy' when the accelerator is depressed. What is the possible cause and is the car safe to drive in its present condition?
Submitted: 2 years ago.
Category: Ford
Expert:  Matt replied 2 years ago.
Hello

On any car if you get a check engine light or other fault light this typically means one or more of the sensors has failed or has a faulty connection.

The ECU senses this and may put the car into 'limp home' mode which typically limits the revs and the amount of power available. Usually the car is safe to drive for a short distance as the mode is intended is intended to get you home without incurring any engine damage

The quickest route to repair is to have the car plugged into a diagnostic machine which will read off the fault code stored in the ECU (providing the light is still on at this point) and indicate which sensor has failed or whether the fault is more serious.

You can do a very rough and ready check yourself by unplugging sensors one at a time and seeing if any of them change the driving condition which would indicate the most recently unplugged sensor is the faulty one. This method is not foolproof though and reading a fault code off is the better method.

from your description though I'd say that this could be an issue either with the oxygen sensor in the exhaust or the MAF ( mass airflow meter)

so it would be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it.
if the engine condition is the same then chances are the meter or the connection to it is faulty


its also worth cleaning the airflow meter by removing it from the car and spraying the exposed sensor wires inside the tube with a brake or switch cleaner - ensure that the cleaner is one of the old fashioned, non Eco type that does not leave a residue

On no account touch the sensor wires with anything physical as they are extremely fragile
Customer: replied 2 years ago.


Thankyou for your comprehensive imput. If the car is plugged into a diagonistic machine and the problem is found to be a sensor fault, how expensive is this likely to be to put right?


 


Also this may seem to be totally unrelated but is there a possibility that the problem could be caused by worn out spark plugs?

Expert:  Matt replied 2 years ago.

Hello Helen

a faulty sensor can be as little as £20 to repair or as much as £300, I'm afraid without more information I can' t make an accurate diagnosis

faulty plugs can produce a misfire which then will then produce a check engine light so it is a possibility

but really the next step is a diagnostic check as this will save you money by giving a quick an accurate diagnosis

Matt, Mechanical Engineer
Category: Ford
Satisfied Customers: 21113
Experience: BEng hons Mech engineering, in auto industry 22 years
Matt and other Ford 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:

    190
    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:

    190
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG Mike Kelly's Avatar

    Mike Kelly

    Ford Mechanic

    Satisfied Customers:

    140
    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.
  • http://ww2.justanswer.com/uploads/FO/fordspec/DSC00877.64x64.JPG fordspec's Avatar

    fordspec

    Ford Technician

    Satisfied Customers:

    11
    ford technician
  • http://ww2.justanswer.com/uploads/AL/allagher/2015-6-23_213635_image.64x64.jpg Gallagher99's Avatar

    Gallagher99

    Senior Vehicle Technician

    Satisfied Customers:

    594
    SVQ LEVEL 3, QAULIFIED FORD SENIOR TECHNICIAN , ATA REGISTERD ,12 YEARS EXPERIENCE
  • http://ww2.justanswer.com/uploads/FO/fordtwo/2014-12-19_163422_arrepair.64x64.jpg Robert's Avatar

    Robert

    Ford Technician

    Satisfied Customers:

    43
    Fully qualified 19+yrs exp/self employed technician in the UK
  • /img/opt/shirt.png Mark's Avatar

    Mark

    Auto Service Technician

    Satisfied Customers:

    59
    Qualified City & Guilds
 
 
 

Related Ford Questions