I've had a search but now more confused than ever (doesn't take much) I have a leak down the back of the engine and bellhousing you can see drips quite high up and this at the bottom...

I base my decision on how long you intend to keep your car.
Assuming a couple of years minimum, then buy some peace of mind and change anything that looks dodgy. The O rings in the water pipes don’t like being disturbed.

Cheers
Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

Could be from the front of the V at the thermostat pipes. I did a thread about replacing them. uV dye is your friend here for tracing leaks . A couple of bottles into the expansion tank and trace with a Uv torch at night.

For example:

I suggest that you remove the donut to have a look for the source(s). If it's just the o-rings at the back then you might continue to replace them. My Viton ones needed to be replaced again at about the same interval. MY21.5 D350 Vogue SE Carpathian Grey

When I had a coolant leak showing at the back it was from the bottom of the thermostat housing.
I did the front o-rings and top of thermostat housing first but still had a leak.
You do damage the housing getting it out but it looks like the o-ring goes flat and they crack around the bottom fitting.

Mike, Much what I was thinking...

Fisha, the bright orange coolant seems easy to see at the moment, when I get it all apart is another matter...

GraemeS Just trying to pre-empt what I might need, can you remember the size of the "O" rings needed...??

Baz8046 Handy pictures, Thanks for them and the info...

Well I've ordered a new oil cooler and filter, and both halves of the thermostat and housing...

Anyone know of anything else to do under there, "O" rings etc and sizes if you have them?

Cheers

Ordered both parts, basically everything inside the two black boxes...!!

Click image to enlarge

Strip down of the top of engine stuff is pretty straight forward Pete. It all looks tight but once you have the secondary bulkhead and plenum off then you can see most of it.  There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

Cheers for that, just trying to make sure I have all the bits so it's not off the road for long...

I get withdrawal symptoms if I can't drive it....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

This may help: https://www.fullfatrr.com/forum/topic66813...+hose+seal 2012 Vogue TDV8 in Aintree green over sand

Cheers, I knew I'd seen that somewhere, used search, never found it...... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

BS611 Viton are good fit o-rings on the turbo oil feed fitting. MY21.5 D350 Vogue SE Carpathian Grey

Cheers, do you happen to know the size of them...?? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

BS611 has ID 8.73mm and CS 1.78mm (OD 12.29mm)

The groove in the fitting is 9mm OD and the hole in the oil cooler is 12m ID. MY21.5 D350 Vogue SE Carpathian Grey

Cheers...  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-