Coolant leak after returning from workshop
 

I got some maintenance work done on my 2005 545 at my local independent workshop - front brakes, brake fluid flush, engine oil change and a battery replacement. I drive back home and the next day I drove about 5 miles to a restaurant and noticed a profuse leak from under the driver side. After going home, I noticed that the leak is still there - nothing shows up on my iDrive. I let the car cool down and in the morning opened up the coolant chamber to see it is almost empty.

I'm taking my car back to the workshop on Monday (will have to get it towed I suppose). My question is - could this be a co-incidence that this happened right after I brought the car back from the shop or could be negligence on someone's part while performing the other work on the brakes, oil change?

Thanks for any insight.

Have you have the typical 545i leaks and gaskets fixed yet? If not probably just a coincidence. If you have its probably just a coincidence anyway, nothing they did should have affected the coolant, unless they are grossly incompetent.

If you didn't have a leak the day before and you do now, it is very likely due to something that took place at the shop.

I certainly didn't have the leak the day before. Now the coolant level low indicator came on as well, so I know the sensor wasn't broken.

I have had the typical 545i gasket leak fixed already.

What would cause the coolant to leak this heavily? This is not a little drip - almost a cup full or more. I don't want to think that my workshop was incompetent but this seems too much of a coincidence!

did you pop the hood and look?
the v8 are known to leak out of a little hole in front of engine, when the cooling pipe fails. or maybe a line is leaking. you need to look and find out.

Until you take a look under there or take it back to the shop for them to look, it's all speculation. If you don't have any coolant to fill the tank I'd tow it to the shop. Also I'd prepare for it being a coincidence since things do break at random times. Just curious which shop did you take it to?

@turboawd I did pop the hood and look - the leak seems to be from under the coolant tank but I couldn't see exactly.

@Booyaazaa. I do have the BMW coolant that I use to typically top off but if it is leaking that heavily, is it advisable to fill it and drive? The workshop is around 3 miles from where I live. Better to have it towed or I could drive it?

If it is leaking from underneath the expansion tank then most likely it had nothing to do with the recent service. Have you felt around the tank to see if it has a crack underneath it? It is common for our expansion tanks to fail starting around 69k-100k mile range. If it is that then you could try to talk to the shop but most likely you'll need to replace it, which is very easy.

If you end up taking it to the shop I'd probably tow it if it is leaking right away when you fill the tank. I was lucky and mine wouldn't leak until the car was nice and hot and when the tank pressurized it would cause a small drip.