v40 1.6 black box top of radiator?
 

Hi all.am trying to sort idling problem on my 2000 volvo v40 1.6.at the top of the radiator on the right hand side is a small black box that makes a ticking sound like a pump.it has a hose running from it to the bottom of inlet manifold.what is it and what does it do.I have replaced the hose as it was perished and appeared to be flat(collapsed) in places.Thanks Alan

I think you may be refering to the solenoid / purge valve for the EVAP system. The other pipe from this valve goes to the carbon canister inside the inner wing. If there is a leak, or the valve isn't working properly, it can cause idling/ running problems. It may show a fault code for this, if you have access to a code reader / scan tool ?
Also, may be worth checking the rest of the pipe work relating to the EVAP system, & maybe the carbon canister for leaks. I think you may need to remove the wheel & the plastic arch liner to get to it ? You may also be able to smell petrol fumes if it's leaking anywhere in the system ?

Thankyou very much for the information.Alan.