Just to echo what Jeff said, (along with owning a V8) I had a smell of coolant too. No drips, puddles, etc. The telltale was when I would put it to defrost, it would fog up even more. I went for the heater core. After it was replaced, problem fixed. I believe the heater assembly is the same for both engine types. Word of advice if you do go for the core, don't buy the part from Atlantic British. I don't think it's LR Genuine (Britpart?) and required really boogering up the heater box assembly to fit it (cutting, grinding, repainting) and the inlet/outlet hose fitings were so close together that I had to soap up the coolant hoses to fit them. This time it would pay to go Genuine.
Once I got the assembly out I expected to see a leak trail or something...not a thing. Even inside the assembly on the core, not a trace.