hi mate
i had a some thing like that happen to me on my astra
turned out to be a knackard oil cooler leeking into the coolant common fault on astras dont know if discos have oil coolers but worth having a look
hope this helps
hi just saying ello
getting a landy in next couple of weeks either freelander or disco td5
just wondering which 1 would suit my needs
tell you what they both got some problems