GQ Mav TD42 what's this thing sticking out side of my block under exhaust?

[bexi]

Hey guys, this thing looks like some sort of cam chain tensioner or something but it's up the back of my block under the exhaust manifold near the gearbox.
might be a stupid question but what is it?
(my std dump pipe on GU turbo is hitting it)

[Tipperb]

G'day are you talking about the galvanised object in the middle of the photo?

[Ade]

It's the oil pump relief valve..