bmw 1999 318i se

[boris30]

when you open the bonnet at the front to the left theres a plastic casing with a silver disc in it
what is it

 

[nickso]

which model? e36 or e46?

if its e46 which engine? n42 or m43?

a pic would help.

 

[boris30]

e46
m43

sorry no pic

 

[nickso]

large flat plastic unit with a rubber pipe on the top and one out of the bottom?

 

[boris30]

a pipe goes under the fan and one to the gasket
when i start my car it makes a stupid noise and when i just touch it it stops

 

[nickso]

sounds like the air pump. it's there for emissions purposes. if it's making noises get it seen to.

 

[boris30]

when i start the car its runs for a boout 2 mins then goes off

 

[boris30]

i looked on ebay and it looks like the air con pump
will this effect the cars running?
it was chugging a bit so my mate changed the fuel filter, spark plugs,oil filter and its still the same

thanks by the way for replying