HELP PLEASE 3.6 TDV8 2006
I have a small coolant leak and everytime i fill to the cold water fill line the next day its dropped 2 inches by no sign of a leak, any ideas welcome.I do get the coolant level low on the dash each time.

Hi

First of abit more information. Have you had the car long? Has it only just started doing it?

Do you have heat coming through the blowers? If not or if it Luke warm you might need to
Bleed the coolant system.

If that is all fine and there are no outward sign of loss then you need to start looking for failed components.
Is the header tank and cap in good condition? The bottom hose can rub at the bottom of the coolant tank.

Then the egr coolers can leak into the exhust and the thermostat housing can crack.
Do you get any white smoke? Is the oil and coolant clean?

You can get a pressure test done on the coolant system to see if you have an external leak or internal leak
Which does not cost much. Check all these things before thinking head gasket. I did and it was the head gasket
But it is a lot cheaper to check these items first.

Good luck

Thank you. I have decided the best course of action might be a coolant pressure test first.

I had a similar leak, turned out to be a pipe that runs in the V of the engine - front to back - got it sorted eventually but it was a few quid for parts and a few hundred quid for labour. Mind you mines petrol so yours may be different, well you certainly wont need to remove the supercharger  Geoff

Feel down the small hose from the bottom of the header tank, it has a tendency to rub and wear through.

Can be swapped pretty easily, much easier with the drivers headlamp out.  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

Thank you.
I had a look today and found the leak and its the pipe from the tranmission cooler which goes to metal pipe and so on, just checked the part number and its around £300 so iam going to repair with a copper pipe joint.