Goffy 39 Report post Posted December 6, 2019 Greetings guys i have noticed my 540I has been using coolant. it came up with a low coolant level warning 2 months ago, (first time in over a year of ownership) i dont do huge mileage just a few 200 km trips so , probably covered around 600 KMs over the last two months. It came up with a low coolant level warning again this morning and it took around 1 litre to fill again. I haven't seen any water on the floor anywhere as i think the leak is really slight. i have removed the cover underneath and i can see a slight weep from a thin plastic mount that mounts the transmission oil cooler. i think i have finally found what the part is called.:it appears to be a Radiator Mounting Plate for Auto Trans Oil Cooler and Thermostat. It looks as if coolant might run through this as it appears to have a seam and there is a slight drip coming off it at the bottom . Is there coolant going through this or am i barking up the wrong tree? see pictures, it is possible the leak might be from above, gravity being what it is although the rest of it seems to be really dry and only the end facing the road appears to be wet. Does anyone have any idea? Thanks for your help! Goffy Quote Share this post Link to post Share on other sites
Eagle 1661 Report post Posted December 6, 2019 Coolant is one side and oil on the other so something will be sealing it to the bracket, maybe this mount plate you are talking about or maybe BMW plastic failure. A pressure test would confirm exactly where without fuss, or you could try cleaning the area up, get the car up to temp and check, if you don't see anything, let it cool down for a bit and check again. Quote Share this post Link to post Share on other sites
Goffy 39 Report post Posted December 6, 2019 Thanks Eagle, really helpful! I will check this tomorrow. cheers Goffy Quote Share this post Link to post Share on other sites
Goffy 39 Report post Posted December 6, 2019 thansk guys i am finding someone to pressure test soon hopefully. i am pretty convinced that part is faulty so i am finding out if anyone on the site may have this part: BMW Radiator Mounting Plate for Auto Trans Oil Cooler and Thermostat - 17117534907 - Genuine BMW cheers Goffy Quote Share this post Link to post Share on other sites
Eagle 1661 Report post Posted December 8, 2019 Don't think would be a commonly available part. Id say it's more likely the 2x o-rings that would need replacing rather than the whole mount. Dealers usually stock those sort of things. Quote Share this post Link to post Share on other sites
