[HTX_BMW]

My 2017 330i xDrive started throwing lots coolant overboard. It started when the weather dropped here in Texas to an unusually low 25 degrees F. The one year old coolant is properly mixed and did not freeze. I examined all hoses, radiator, etc. that was visible in the front and top-front of the engine with the cowls off. The coolant is coming from somewhere in the rear or rear-top of the engine when I can't see. I took it to the shop and they are saying they THINK it's the oil cooler heat exchanger. Of course they have to remove/disassemble the intake to get to this area to confirm the diagnosis. They are quoting $2500 for this job. I do trust the shop; I've used them for years, but this seems like a lot of money to confirm a guess. Have any of you guys heard about a coolant leak from the oil cooler heat exchanger? Is there a more likely place to examine. BTW, I did have that small plastic part of the cooling lines that was just recalled replaced. Mine broke right before the recall of course.

[alexonahurry]

My coolant has disappeared very slowly but steady and it was the oil filter housing. I then have also changed the vent line as preventative maintenance and the BMW dealer charged $1500 Australian - my car was there for 2 days and it was quite a big job. My car only had 45.000km when it happened.

[MidtownMike]

Suspicious that this started right after the hose replacement (they should have replaced the entire hose, not just a small plastic part). Could very well be that they did not mount it correctly. Maybe have it checked under warranty?