A140 running poorly after maintenance

[Lauwrence]

Hello all,

Quick introduction: my name's Lawrence Robinson, 36yrs old, residing in the Netherlands. I came across this forum thru Google as have many others before me I'm sure

My wife owns a 2001 A140 which has never really given us problems, until recently. The car was brought to a none Mercedes garage for its periodic maintenance whereby fluids, filters and sparkplugs were replaced. All seemed fine until I took the car for a drive myself and noticed it holding back when accelerating accompanied by stuttering in low revs. Odd how my wife never noticed this...

Sure enough next day (3 weeks after AM maintenance) the boardcomputer came on with an engine problem on the dash. Car was returned to the garage, the nitwits simply reset the light and never even gave the cause a second look and of course the light came back on the same day.

The car was then brought to Mercedes who then took 3 days to find the computer had logged a list of errors, mostly referring to 'lean mixture' problems. They cleared the log, took the car for a drive a few times to let the computer (ECU?) adapt to the engine and returned it to us.

Make a long story not unnecessarily longer, the engine's running fine mostly now, but the light remains on. Mercedes have already said they'll replace the computer completely, of course quoting a massive price.

I'd very much like to hear about your ideas on this issue?

Thanks in advance.

Lawrence Robinson

 

[GEORGEROV]

Hi Lawrence, Aye, the garage will replace the computer but I'll bet the light will still remain on!. Sounds like there is a fault with a sensor and the ecu is recognising the fact. You say the engine is running fine 'MOSTLY'!. I take it that means its not really 100%!. I would tend to believe the ecu rather than the garage!.

 

[Lauwrence]

Hello Georgerov,

Thanks for your reply!

I've done some further investigating and now think the airmass sensor may be to blame here, although it's still a bit odd it'd start acting up right after maintenance. I can only guess the sensor is contaminated somehow, so my first action will be cleaning it.

 

[colechelle]

Not a lot of point, new one needed!!!!!

 

[Lauwrence]

Before anyone believes this thread is either dead or the problem's gone, I've a small update on the matter.

As said the car ran fine mostly however behaviour had started to deteriorate a great deal as of recent.

The ECU has been removed and sent away for repair. I'll post back about the outcome of this technical adventure.

 

[television]

Thanks for the update, I am sure it will be the O2 sensor that put the lamp on, but I do not know the A class that well

Please keep us informed of the progress

 

[power-steering]

Hello all,

Quick introduction: my name's Lawrence Robinson, 36yrs old, residing in the Netherlands. I came across this forum thru Google as have many others before me I'm sure

My wife owns a 2001 A140 which has never really given us problems, until recently. The car was brought to a none Mercedes garage for its periodic maintenance whereby fluids, filters and sparkplugs were replaced. All seemed fine until I took the car for a drive myself and noticed it holding back when accelerating accompanied by stuttering in low revs. Odd how my wife never noticed this...

Sure enough next day (3 weeks after AM maintenance) the boardcomputer came on with an engine problem on the dash. Car was returned to the garage, the nitwits simply reset the light and never even gave the cause a second look and of course the light came back on the same day.

The car was then brought to Mercedes who then took 3 days to find the computer had logged a list of errors, mostly referring to 'lean mixture' problems. They cleared the log, took the car for a drive a few times to let the computer (ECU?) adapt to the engine and returned it to us.

Make a long story not unnecessarily longer, the engine's running fine mostly now, but the light remains on. Mercedes have already said they'll replace the computer completely, of course quoting a massive price.

I'd very much like to hear about your ideas on this issue?

Thanks in advance.

Lawrence Robinson

Hi Mate,

Believe the ecu not the garages (ESPECIALLY the dealer)

It's your air mass unit which is built on top of the ecu, it's a very common fault on all a-class mercedes unfortunately and 9/10 times we can remanufacture them with a full 12 months warranty - ONLY if your car is manual.

If your A-Class is automatic transmission, then unfortunately you will require a new/replacement unit.

If it is manual, give us a call on 0208 853 3343 so that we can help you further (ask for myself Jay or Danny).

Goodluck

Cheers,
Jay