Excessive Black Smoke

[nultyg]

Hi there,

Having issues with the old dear smoking (C270 CDI 2002), i have tried the usual full service and have now replaced the Mass Airflow Sensor - still the same.... however when i disconnect the MAS the excessive smokes goes away but i have no kickdown..... any ideas what might be causing it ???

 

[Dieselman]

I'd be looking at the EGR valve.

 

[se97mlm]

Me too...

MAF sensor is used for EGR rate regulation, if the error code "MAF unplugged" arises it may disable the EGR.

COuld be that the EGR valve is too wide open/stuck open at any given point

Regards

Matt

 

[BlackC55]

Thirded EGR. Around £270 from a dealer

 

[nultyg]

Thanks for that ....i'll investigate it further ...and feedback the findings... any idea where the EGR valve is located ?

 

[Dieselman]

ITEM 47

 

[KLP 92]

ITEM 47

Item 47 seems cheap for an EGR valve. £93.73 + Vat from MB online.

For that price i may just change mine on the 270, it likes to puff a bit

 

[cheshirecat]

new boy question, why not just clean it all out including the manifold and then disable, will it throw a fault or does it depend on the type of ECU

 

[cheshirecat]

new boy question, why not just clean it all out including the manifold and then disable, will it throw a fault or does it depend on the type of ECU

BUMP

 

[Parrot of Doom]

You can't disable the EGR on turbo models. Theres far too much electrotrickery going on.

 

[Dieselman]

As POD says, the MAF sensor will detect the lack of EGR valve operation and throw the ECU into limp home mode.

 

[nultyg]

Hi all,

Thanks for all the replies above, and apologies for taking so long to reply.

However, problem solved - after some under bonnet investigation i found i had a split on the Turbo Manifold Inlet pipe ( Black Rubber Hose) aparently common on this model.

So replaced the hose and everything is tickety boo ...

Thanks to all involved.

Gary