Need help with what this part is please
 

Hi just bought a cheap Audi a3 02 plate 1.6 petrol and a part has split and is spraying the coolant all over the place, have googled but cannot find out what this part is so any help much appreciated,
Cheers in advance

Would have been helpful to indicate which part in the picture is split spraying coolant all over the place. I'm assuming it's not the green thing (which is your temp sensor) but the plastic housing it sits in. I have absolutely no experience with that car but from the looks of it I would guess it is the thermostat housing.
Google that for your car and it comes back with part number: TT596-221

Good luck!

Sorry using my phone wasn't able to edit the picture at all and thank you for the help got the part order and cheers for the help