If you plan on keeping the Rover order this right now ULTRA GAUGE. Get yourself familiar w/ the features and make sure to set the Engine Temp reading on the main screen so it's clearly visible. The factory temp gauge is absolutely worthless. SB will show you pics to back me up.

You are probably hearing the rushing water sound because it's low on coolant, again. Fill it up to the factory recommend level when the engine is cold, keep your finger crossed, and monitor the coolant levels.

Do you have any white smoke exiting the tail pipe during cold starts? Or operating temps for that matter?

 

I do want to keep it its been a great truck at first but recently I've been getting more problems and I don't make as much as I use too so depending on repair costs I may end up having to get rid of it and I want to keep it since it was my first vehicle.

 

are you sure you dont have any hoses that are leaking when the engine gets up to operating temp? Also look at the bottom of the coolant tank they are notorious for wearing out at your mileage.

 

I'm not sure if the hoses are leaking but I did take some pictures of where it looks like its coming from. One of the pictures is from before I cleaned most of the oil and coolant off because the bottom was covered in it.
Land Rover - Imgur

 

get a pressure test and check it out from the height of some of that cooling I would think the rear of the head gasket or intake gasket, but you will never know unless you put a pressure tester on it.