w211 e220cdi rough idle when cold

[haydar]

As the weather is getting colder, my e220cdi has started to idle very rough in the mornings. At the same time it's blowing out loads of white smoke from the exhaust. Then 2+ minutes after start it all clears up, idle becomes smooth and no more smoke from the rear.

Using the STAR diagnostic system, everything seems fine except the MAF and injector quantities, which are both high. This points to unburnt diesel being the white smoke as apposed to engine oil. I think is confirmed by the fact that the car does not consume engine oil.

Now even when the car starts to idle normally, the MAF is still over reading. I've replaced the MAF several times and it always over reads!

What could be causing this??? If there is a air leak in the fueling system, wouldn't that be there constantly and not only for the 2-5 minutes after first startup in the morning? It could be the injectors but they were replaced.

There is the posibility the car's ECU has been reprogrammed, so I've tried reprogramming the ECU via the STAR system but I keep getting a 'communication error 8.600'!!! Anyone know what communication error 8.600 is??????

Thanks

 

[BlackC55]

The communication error is because the software you are using is not correct.

You can't re-program the ECU without the proper SCN coding and update discs.

Is the after glow system working for the glow plugs?

 

[haydar]

Hi BlackC55

The software is the official MB software at an authorised MB dealer? My car is an early w211 so I'm thinking that they must have the updates for this car by now? I also tried another non offical MB garage who claimed to have the very latest software and again we got the same error. The SCN code was obtained from MB Germany using their web portal for authorised dealers.

I did have the glow plugs replaced, and the car starts on the button, though of course the rough idle. Is there anything I should be checking regarding the glow plugs? Also, wouldn't the STAR system give an error code?

Thanks.