Slow coolant leak on 04 X5 3.0i?

[NardoW12]

Have a 2004 X5 3.0i, with about 125K miles on it, the water pump and belt were replaced not too long ago.

Recently I noticed the coolant's been leaking, and I got the check coolant level warning on the dashboard. It seems like the coolant leaks really fast right after I top it, and gets slower after it leaked past a certain level. I have been driving the car very carefully since I start getting the coolant level warnings, but it seems like the coolant temp is normal with or without the check coolant message.

Anyone had similar experience?

[epdarks]

Most likely the radiator.

Replace along with the thermostat.

[SlickGT1]

Expansion tank maybe. More info needed.

[Elvis 3.0]

When cold wipe down engine bay entirely especially expansion tank as Slick suggested and all hoses. Dry clean. Top off coolant with BMW coolant only (assuming you have not made mistake of using another type) 50/50 mix with distilled H2. After 48 hours park car out of sunlight (for easier viewing) and drop a 2'x 4' cardboard / paper under engine. Take a good look with a strong flash light or other light [even in day] for dried coolant. Look along seems of expansion tank, radiator, hoses, hose ends/clamps. I am pretty certain after you do this it will be less of a mystery.

[NardoW12]

Thanks for all the replies guys, took it to a shop today and they did a pressure test, turned out that it's the coolant tank that's cracked, getting it replaced on Friday