Last night after about a 20 minute ride home going out 80. When I got out of the car I heard this bubbling sound, almost like hot water in a pot. When I opened the hood, it appeared to be coming from the coolant tank. Obviously I didn’t dare open then. I have never noticed that sound before. I don’t notice anything leaking or any odd smells. Please help

 

did you get any msgs on idrive

 

Did you go to the dealer recently? My dealer over-filled my coolant bigtime. It's probably just overfilled.

After the engine is cold, check the level, if it is really high then that's the problem

 

Run the engine with the cap off. let it get warm. if you have bubbles it may mean a leaking Head gasket, especially if there is any white smoke comming out of the tail pipe when you start the engine after it sets a while.

 

Nope no messages on the idrive. I did however just try the temp gauge tirck and went for a drive. I was pretty stable at 105 degrees. However oddly enough I randomly just got a low oil light. Just checked my oil and it wasnt low. I am not sure if I threw something off wack by going through the menus to get the temp guage trick to work

 

Not sure it's a good idea to let the engine get hot without the cap on. These engines run at 105?C, which would be over the boiling temperature of water at atmospheric pressure. It seems to me that the cooling system must be pressurised for the water not to boil, so if you remove the cap then the pressure cannot build up and the water risk boiling?

 

Yes, check the level when it's cold. Could be low or high.

Did you do anything to your cooling system recently? Maybe air in the system? There's an automatic purge program on the 545, search and you'll find a pdf from TIS on this forum.