W203 M112 Noob Questions

[Peter Broomfield]

Can anyone tell me what these are and what they do??? (Red circled)
(Not sure why the images rotated??)

1)
This one puleses


2)
This one clicks

2001 W203 C320

 

[LostKiwi]

First picture looks like the heater water circulation pump (which provides circulation of hot water when stopped and the Rest button is pressed.
The second one is the Evap system purge valve.

 

[Peter Broomfield]

Sorry the pics roated, not sure why and thanks for your answers, havnt got myself a Haynes manual yet.
First one does pulse, you can feel it through the pipe, quite the pulse too!!

Noob question time, whats an Evap system purge valve for / do?? mine clicks every so often, sounds like a relay clicking on and off.

 

[LostKiwi]

Evap purge is part of the emissions related gubbins. Its there to vent fumes in the tank. Normally extremely reliable and rarely gives trouble.

For the first one do the pipes leading too/from it get hot? If so it confirms its the circulation pump but normally tehy don't pulse as far as I'm aware.