X5 (F15) M50d coolant leakage problem

[sysung]

Hi gurus,

I am an owner of 2014 X5 (F15) M50d (manufactured in July 2013) owner residing in South Korea.

I have been running into this coolant leakage problem every 1-2 weeks for the last 6 months and the problem still persists even after 5 times of checking/fix by official BMW Service Centre in Korea. BMW Korea proved themselves that they just do not have enough experience/capabilities to deal with this sort of complicated problems, so I am turning to folks overseas who might have faced similar problems, especially with tri-turbo diesel engine, with a hope to get any clue to fix this problem and end this nightmare.

I have noticed the leakage happens immediately right after high-speed driving (over 100mph), but happens on a bit slower cycle during normal driving conditions (e.g., on every 2-3 weeks).

BMW Service Centre Korea has replaced coolant tank once, claiming the leakage was happening on the cap of the tank, and later after continuing leakage, they replaced EGR cooler, claiming there was leakage found in the cooler this time. But again the leakage still persists. In other 3 times of checking, Service Centre did water pressure check only and told me everything is normal.

As BMW Korea is not making any effort to get this problem fixed, passing the buck to their Service Centres run by dealership (BMW Handok Korea), I am desperately seeking help from those who have gone through similar coolant leakage problems and have found possible solutions, aside from taking legal action against BMW Korea. (Currently looking into a feasibility of legally holding BMW AG accountable for this problem as well.)

Any advice, comment or insight to help with this leakage problem would be highly appreciated.

Thank you!
Brian

[ajob]

If BMW can do it in your country, get some UV fluorescent dye added to the cooling liquid, drive a while with it and then inspect the whole engine in a dark room with an UV lamp to find the leakage.

[sysung]

Sounds like a briliant idea! Very helpful.
Thanks a lot ajob!

[42pilot]

Where is the leakage exactly? From where? I have an idea but I need to know where the leak is coming from. Take a picture if you can. We had a similar problem with Ford Powerstrokes but it was always from one place on the engine. Look closely at the coolant cap.

[sysung]

Dear 42pilot,

Thanks a lot for your feedback.
Unfortunately, there is no visible leakage ever found under the hood, especially around cooling system.

I have a few times tried to see if there is any leakage mark around coolant tank/cap and hoses by cleaning them before driving, however, there has never been any leakage spot found even after I get new low coolant level warning. BMW Service Center replaced the entire tank/cap once, but it did not help.

Coolant capacity of F15 M50D is 15.4 liters. Whenever I get low coolant warning, I usually add 1-2 liters, which I don't think is inconsiderable. There were a few cases with F10 M550d (with the same tri-turbo engines) which had coolant leakage inside of engine, so I carefully presume mine belongs to this case.

Service Center once claimed there was a clear leakage inside of EGR cooler and they replaced it, but again it did not help at all. They are not willing to investigate a possible leakage inside of engine, but doing only water pressure test, which makes me frustrated.

Anyways, any tip or idea based on your experience would be of great help here!
Thanks again!

[42pilot]

Wow. I was going to suggest the EGR since that is a root problem for many diesels. If the coolant was coming from the cap, I was going to suggest a blown head gasket as this is another problem with EGR diesels. I wish I could help and I think BMW needs to be helping you a bit more. Clearly, the engine is consuming the coolant somewhere...

[sysung]

Thanks a lot 42pilot for your help anyways.
Currently knocking on doors at BMW HQ to seek any possible support and hopefully they would give attention to this matter and help find solutions.

[42pilot]

If there is no coolant in the oil (I am assuming they checked that) and there's no coolant on the ground, the engine has to be burning it through the head gasket or the EGR system. Ask them if the turbo's center section is water cooled. If it is, that's another possiblity.

[sysung]

Thanks a lot for the advice 42pilot.
Will look into it. Thanks again!!

[DeltaFX1942]

Did you ever get your issue resolved? Have you tried Kolon's service department?