I have observed that my 2003 V8 disco is loosing coolant. As I have not possibilities to look under the engine i do not have real reason of this leakage.
I have checked oil filling cap (demaged head gasket or something...) and have observed some brown residues like coffe grounds inside the cap. Does it means that head gasket is damaged??
Sorry for my english.</SPAN>

 

Caked oil inside the valve covers is a sign of neglect of oil changes, but nothing more. It does not say anything about the head gaskets.
Check your oil for coolant, it will have a chocolate milk shake look if coolant and oil mix. Assuming you have eyes and are not physically disabled you should easily be able to inspect the engine for coolant leaks. Check the throttle body heater, water pump area and all hoses for leaks.