Can anyone tell me what this is?

[glynn09]

And should it be making a clicking noise? Seems to be some sort of pump, that turns on and off. It's only clicking when its on. I've not noticed it before, but I could just be being paranoid, as I'm in the process of selling the car.

It's a w210 e55, just in case it's engine specific.

Regards

Glynn

 

[stevesey]

Valve for the fuel evapotative loss control system.

Vents the charcol canister (under front wing) connected to the fuel tank into the inlet manifold. Often "tick", sometimes more than others (mine is disconnected from the mouning block to reduce noise tranmitted into the body).

Value is closed for first couple of minutes after a start, then pulsed (hence ticking) to vent the fumes from the charcol canister/fuel tank (regulations prevent you releasing fuel vapour to the atmosphere).

 

[glynn09]

Thanks for that, greatly appreciated.

Kind regards

Glynn

 

[Smiley]

My R129 SL500 ticked quite loudly; first time I heard it I had the fright of my life!

 

[recycled]

i blame the green people. scared me as well when mine was ticking