Afternoon all,

Silly question / query. Had the oil cooler replaced recently on my MY2016 4.4 SDV8. Subsequently keeping an eye on coolant level in the expansion tank as air locks have bled off.

I’ve found when topped up that it finds its level just below the oval cut out / hole that’s visible when looking inside the tank with cap removed. When I’ve topped up just lapping over this level it seems to settle back to just below.

Looking at the side of the tank with the engine bay trim removed the exact level not entirely clear but can see approx at max when cold.

So my question is could others advise where their coolant level tends to level out in relation to oval cut out as a reference point?

Just wanting to ensure I’m not suffering slow coolant loss etc ……. Current
2016 MY L405 SDV8
2018 VW Golf GT EVO
2001 BMW Z3 2.2
Previous
2002 L322 TD6
2004 Mercedes R230 SL350
1994 993 Carrera
Range Rover P38 x3
Range Rover 3.9 EFI

My oil cooler gaskets needed replaced, once done I also noticed the same as you. Topped up level ( to oval hole inside bottle) and noticed that level would slightly drop when checked. It would not drop much just a cup full to fill back to mark, and this was after weeks of job been done. Pressured tested system- No drop in pressure or leaks. Stripped down again to check -all ok. In my opinion is that the system is large and ( if fitted) goes though fuel burning heater etc. so lots of places air can be trapped.
I have just topped each time low and monitoring it.

Mine always drops to just below the oval cut so you cant see it without removing the trim but seems to settle there and not lose any more.

Mine took over 300 miles to settle down to around the top of oval after a new water pump fitted. Thanks for the reminder that I haven't looked for a while so just checked and after another 330 miles it's towards the bottom of the oval (but still in the oval). A miniscule difference that I'm quite happy to attribute to ambient temperature. Chris

2014 FFRR 4.4 SDV8 Autobiography Barolo Black
2012 RRS SDV6 HSE Baltic Blue
and before I saw the light:
2011 Suzuki Grand Vitara SZ5
1998 Ford Mondeo V6 Ghia X
1990 Citroen BX GTi
1973 Triumph GT6

Thanks gents, that ties in with how mine has settled in terms of level. Much appreciated  Current
2016 MY L405 SDV8
2018 VW Golf GT EVO
2001 BMW Z3 2.2
Previous
2002 L322 TD6
2004 Mercedes R230 SL350
1994 993 Carrera
Range Rover P38 x3
Range Rover 3.9 EFI