what does this bit do?

[Miffy]

I have seen a few diff engines of similar type to mine and so far, most of the others either have nothing there at all, or some have the mountings and wiring but thats all. items circled in yellow, what are they, what do they do and why do I have them and others not, answers on a postcard

 

[roofless]

air pump thingy http://www.detali.ru/cat/oem_mb2.as...GA=722.607&CT=M&cat=19Y&SID=14&SGR=105&SGN=04

 

[luders79]

They are the components for the secondary air injection system ! comes in from cold start to help aid the warming up of the cat! for emissions reasons!

 

[Miffy]

any ideas why some dont have it then?

 

[luders79]

got a feeling that its more of an age related thing! most of the later cars with that 112 engine will have it its more the earlier stuff that some have it as an option and some don't! got a feeling the date was aorund 2001 the really push it through! i can only think that mercedes knew tight emissions controls were coming in to force so they ried it out first? some one please correct me if im wrong !

 

[Miffy]

ah, makes sence thanks guys

 

[Cole@MBS]

got a feeling that its more of an age related thing! most of the later cars with that 112 engine will have it its more the earlier stuff that some have it as an option and some don't! got a feeling the date was aorund 2001 the really push it through! i can only think that mercedes knew tight emissions controls were coming in to force so they ried it out first? some one please correct me if im wrong !

Your 100% correct Sir!!