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.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask Malcolm Gillespie Your Own Question
Malcolm Gillespie
Malcolm Gillespie, Mercedes Technician
Category: Mercedes
Satisfied Customers: 1398
Experience:  City & guilds pt 1 & 2
22484842
Type Your Mercedes Question Here...
Malcolm Gillespie is online now

My car want rev over 3000 rpm am there black smoke from

Customer Question

My car want rev over 3000 rpm am there black smoke from exhaust
JA: How many miles are on the car? How has your mileage been lately?
Customer: 142000 miles an ok there no engine management light on or anything
JA: What is the model/year of your Mercedes?
Customer: C Class 2.2 diesel an it’s a 2008
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: At first it said cylinder one was down so replaced fuel injector then I was getting the black smoke it then give me a code of p0263 contribution/balance then put a brand new injector in cylinder one drove it seemed of then went into limp mode still no engine management so don’t have a code to say why
JA: Is there anything else the Mechanic should know before I connect you? Rest assured that they'll be able to help you.
Customer: no
Submitted: 9 days ago.
Category: Mercedes
Expert:  Malcolm Gillespie replied 9 days ago.
Hello my name is ***** ***** thank you for using just answer. I suggest having the 16 pin obd codes read with a suitable scanner , the code or codes will point us in the right direction saving tme , money and guessing.
Expert:  Malcolm Gillespie replied 9 days ago.

I suggest checking the MAS meter and the EGR

Customer: replied 9 days ago.
It isn’t giving me any codes at all to why it won’t rev over 3000 rmp
Expert:  Malcolm Gillespie replied 9 days ago.

Please read above.

Customer: replied 9 days ago.
How to I check the MAS meter
Expert:  Malcolm Gillespie replied 9 days ago.

Remove the sass air flow meter and check the centre bimetal strip is clean and not covered in oil.

Customer: replied 9 days ago.
That seems ok checked that an it had a tiny bit of oil on the corner which I wiped
Customer: replied 9 days ago.
Do you mean the element inside the air flow sensor
Expert:  Malcolm Gillespie replied 9 days ago.

Yes , when dirty it causes this problem normally renewal is required.

Customer: replied 9 days ago.
It only start doin this when I changed the fuel injector up until then it ran as it should
Expert:  Malcolm Gillespie replied 9 days ago.

Ok   Just a thought did you reprogram the new injector.

Customer: replied 9 days ago.
No haven’t done that would that mass air flow sensor stop it going over 3000 rmp an if it was down to that would the engine management light come on
Expert:  Malcolm Gillespie replied 9 days ago.

It can cause this and it wont always show a light on.

Customer: replied 9 days ago.
Just check the element through where the air filter goes an it does look like it’s got oil on it an around it
Customer: replied 9 days ago.
No haven’t had the injector recoded
Expert:  Malcolm Gillespie replied 9 days ago.

Ok a good test is disconnect the harness to the sensor and see if it revs up . If it does then new sensor required.

Customer: replied 9 days ago.
I tried that this morning an it doesn’t rev up just goes up to 3000 rmp
Expert:  Malcolm Gillespie replied 9 days ago.

ok

Expert:  Malcolm Gillespie replied 9 days ago.

Clean it and see if a difference.

Customer: replied 9 days ago.
What should I use to clean it
Expert:  Malcolm Gillespie replied 9 days ago.

Brake cleaner or electrical spray will be good.

Customer: replied 9 days ago.
If I clean that what else could it possibly be
Expert:  Malcolm Gillespie replied 9 days ago.

I cant think of anything at the moment.

Customer: replied 9 days ago.
Ok would egr valve have anything to do with it or any other sensors
Expert:  Malcolm Gillespie replied 9 days ago.

I mentioned EGR on second reply

Customer: replied 9 days ago.
Would the engine management light not come on for that either if it had failed
Expert:  Malcolm Gillespie replied 9 days ago.

No it wont but it would be stored in codes.