Recently bought a 99' DII. Seemd to have had a bit of work done by the original owner ( 1st), including heads, alt. starter, radiator hoses, water pump, etc.

I bought it from a questionable-looking guy (2nd) that was unemployed and needed money bad for $1800. He attmepted to do front brakes with Kragen cheapo pads, without replacing the warped rotors ( didn't cure the wobble); then ran out of money. It was filthy to say the least.

Got it fully serviced: Oil & filter ( Mobil 1), transmission service, coolant flush, brake system flush, air filter, transfer case drain and refill, differentials same. Also replaced the leaky valve cover gaskets, and assorted missing trim pieces.

NOW, I have a sloshing sound in the right side of the dash, loud. There are no leaks anywhere, whether sitting overnight or driving around. Nothing inside the car.
WTF!
What is the sound? Was the cooling system supposed to be pressurized or something when it had the coolant drained..........?

 

This is coming from a mechanic background, but keep in mind, I have never worked on a Land Rover before. Your situation sounds pretty generic to me though, because my own personal Caddy STS had the same issue.

The system was incorrectly bled and there was air trapped inside, causing water/coolant to slosh around while being pumped with the air pockets in there. I don't know how to bleed a Land Rover though, but make sure the air is ALL out, and thw sound will go away.