[Lfk]

My 2019 G20 has a slow coolant leak (goes under min after 2 months of topping up and I get a warning). I've had it looked at by three independent mechanics (the ones with the best reviews around me) and each one diagnosed a different problem. All three did a pressure test (or that's what they told me).

The first one told me the leak was from a hose. The second one found it to be from the oil filter housing and wanted to replace that including the heat exchanger. And the third one thought it was the thermostat.

The third one recommended I replace the oil filter housing and heat exchanger with the thermostat because "that's probably going to leak as well later", presumably because replacing the thermostat damages its seal.

At this point I'm really not sure what to do. Obviously at most one (possibly none) of these people is right. What would you do? Is finding a leak really so complicated?

[Delighted_Jester]

If theres nothing obvious under the hood, id climb under and remove the splash shields. Its a pain but i imagine itll let you see up under and around the intake where the thermostat (electric), oil filter housing, etc.

[Sambrownrva]

Hi all--I have a new-to-me 2020 330i XDrive I bought as a CPO from a BMW dealer. Coolant was low when I bought it (but still within the normal range per the gauge inside the reservoir) 4 months ago with ~38k. I topped it off to mid-range on the gauge and the dealer topped it up to Max during its last oil change. Now it seems to be slowly dropping again. How much coolant consumption are you guys seeing/living with versus taking in for a diagnosis? Thanks!