2.0 HDI leak

[oscar]

Hi have a water leak that looks like it's coming from what looks like a cover on near side/left side of engine(above gearbox)has green plug on a sensor there but noticed a seep onto flat housing below where loom runs across.
What is behind box/cover etc will have a more in depth look but just getting over sorting battery out that just died on me while sorting that out found wet patch it did leak from bleed valve then tightened that up so don't think from there mind end of cap is worn where plastic cover rubbed on it till lobbed that out.

It's a 2001 Yreg in picasso

another thing while at it does anyone know where the earthing point is on gearbox as have a problem which Citroen guy says is to do with earth point as builds up resistance as point gets corroded!
Or is it best to run an earth from somewhere else to somewhere else?

[SaabC5]

Thats where the water temp sensor was located on my 2002 HDi.

[Peter.N.]

The earth connection generally goes under one of the starter bolts.

Peter