E240 1999/2000 Model engine problems

[matthillier]

I need some help.

My car has developed a fault which I hve taken to the local garage but they have drawn blanks in all directions.
They have put it on a diagnostic computer and trouble shooting computer without any results.

The problem started when I used the kick down to overtake a vehicle. As the engine revved the gear box changed down gears however it didn't seem to engage properly and the car started to crawl rather than pull away....as if in the wrong gear.
Since then the car struggles to pull way properly...the revs increase however the car simply crawls even when the revs are right up high....it will then gradually pick up up speed and pull away....again alsmost as if it is in the wrong gear.
On a number of occassions the car has almsot stalled...definately not right for a automatic.!
The car will comfortably cruise at 70/80mph however as soon as I accelerate to increase it again feels as though it has selected the wrong gear.
I seem to have an increased petrol consumption...however I put this down to needing to rev so dam much to get going.
The garage have changed the plugs(were needed) but no change and they have checked the cat as well as the diagnostic machine...they have now told me that they have drawn a blank.

I need some help, is it possible that their computer is not fully compatible with the car???

All replies I thank you for. Regards

 

[Cosworth]

What about the Air Mass sensors. Disconnect and see how the car runs.

 

[jibcl500]

Air flow meter, get one from a Bosch service center near you at a lot less than MB prices.

jib

 

[matthillier]

i should have mentioned in my initail thread I am a complete car novice when it comes to anything other than driving it....What about the Air Mass sensors....what would these do??

Cheers

 

[Cosworth]

I believe it measures the amount of air intake into the car.

Its the electronic device between the airfilter and intake pipe.

 

[matthillier]

would this have shown up on a diagnostic machine??

 

[Cosworth]

Not sure, try and disconnect it and drive the car.

 

[jibcl500]

Yes it will show up on a diag P0101 I think the code is, where the air filter is in the engine bay, front left corner, you will see the meter there with a plug going to it. with the engine ticking over remove the plug, the engine should stall within 4 seconds.

jib

 

[jibcl500]

Air flow meter measures the amount of air and air temp.

jib

 

[jibcl500]

Sorry me again, fitting a new maf wont need any diags once fitted as they are self adating and the car will know the maf is good again, the error code will still be logged but it wont change the way the car runs with the new maf fitted and can be erased at a later date.

jib

 

[jberks]

Qyestion. You describe poor running and no power which is indicative of the ECU's safe mode and quite possibly the MAF, but the tell tale is that if you turn off the engine and restart it, all should be well (until it goes again). Does it do this?
I've had one go on the motorway on an E240 and yes, it became gutless but there was no revving aside from me having to drive it harder to get anything over 40 out of it.
The other tell tale was that the idle was as lumpy as a trabant with a missfire and about as powerful off the line.
If all this sounds familiar I think we're all on the same sheet but the fault is that common that if your mechanic didn't spot it, he's not qualified to work on a Merc and will cost you money in the long run. Find someone else.

 

[matthillier]

If the engine stalls does tht mean that it is working ok or does it confirm that is what the fault was?

The garage I used said that no codes came up...is that unusual? would it make a differance if they didn't use a specific MB diagnostic machine.

I really appreciat the advice. Cheers.

 

[matthillier]

In answer to your question (jberks) the fault seems to be inconsistent in as much as I have just driven it this morning and it drove ok, not perfect .... sometimes I start her up and it will pull away with a reasonable amount of power (still not perfect by a long shot) and other times it is struggling to move nd can almost cough splutter and stall. Its very difficult to explain but it feels almost as if sometimes you need to wind the power up and when it reaches a certain level it will pull away similar to trying to pull off in the wrong gear in a manual....feels like alot of effort from the engine with only a limited return on the output....hope that makes some sense. Appreciate the help.
The garage by the way is only a small set up on the outskirts of the village Im in...originally didn't want to drive it to far in fear of causing further damage!
This is why I wonder about their diagnostic machine?!?

 

[jibcl500]

I use carsoft, its the original package not the type found on ebay, it picks up faults no problem, if your local to ely cambs pop it in for free.

jib

 

[jberks]

Sounds a likely canadidate, though my O2 sensor went at the same time and the symptoms of that were a delay in throttle response, so I'd ease my foot down and it would pick up, though not properly, and then a couple of seconds later the rest of the power would arrive. In my case a local specialist identified the O2 sensor but the MAS gave out whist we were waiting for the part so I had both replaced at the same time.
Unplug the MAS. In theory it should run better without it,if it's defective. If it's ok, I belive it will stall. (People correct me if I'm wrong here).

 

[cj...]

Sound like air mass sensor to me.same thing was happening on my wifes c230 komp as she only uses it to go work which is 1 mile down the road and back so it never goes over 40 mph with the engine never under any labour (early morning traffic jams).
I used the car 2 weeks ago for the evening just to meet some friends which inolved a 20 mile trip on the motorway just to give it a blast and the same thing was happening- changed the air mass meter and it is now fine.

 

[matthillier]

Thanks for all your input.

Sensor replaced yesterday and she is driving like a dream.

Cheers.