i ve a 2002 freelander it produces an unsual sound like the one from a diesel powered engine. cud anyone tell me wats wrong please?

Often a noise like that is valve lifters, but the Land Rover uses non adjustable hydraulic lifters. First thing to do is check your engine oil..low oil will do that. Other sources of unusual noise could be a worn bearing on any of the belt driven devices on your engine. Or id it's real loud knock, worst case scenario is a broken piston rod. There are so many other possibilities though...those are just what comes to mind first

Has it always made the noise? One new thing that everyone is going to have to get used to is Direct Injection. It squirts fuel directly into the cylinder for more efficient burning and it also cools which allows for more power. They operate at a higher fuel pressure and make a noticeable noise when they open. -- I don't know if your Rover has them but they have the same sound as a diesel engine since they use the same type of injectors.