As I was pulling my 2010 R52 into my driveway I started to see white smoke coming out from under the hood. It quickly grew into a massive cloud of white smoke and burning smell. I instantly reversed out of the garage, looked at the temp gauge (it was normal) grabbed my bag and stepped out of the car.

When it dissipated I opened up the hood and saw coolant had sprayed inside the engine bay. I check the oil dip stick and the oil looked normal. There was no coolant on the floor, whatever leaked evaporated almost immediately. The coolant expansion tank was completely empty.

Once the car cooled, I started it just enough to pull it back into the driveway, no lights of any kind came on.

I suspect a coolant hose must have failed, I think it must have been an upper hose because there was no coolant on the ground.

Any ideas?

 

Whatever you're checking into with regards to these coolant plumbing, do yourself a favor and check the friction wheel and water pump contact. Mine got melted down and friction wheel froze completely, causing some major coolant issues. Didn't get to white smoke, though. Good luck.

 

I just went through something similar in my R56. There was a tee right below the expansion tank that snapped off in two places and I lost half of my coolant. Ended up having to replace the thermostat and water pipe (which broke when I removed the thermostat). The plastic parts get brittle and fail.

 

DING! DING! DING!

It was the plastic T junction into the upper expansion tank. It snapped at the bottom and sprayed the contents of the expansion tank right onto the manifold and heat shield (hence the insane instant cloud of vaporization)

The T was only 6 bucks, It was a bit of a ***** removing the clamps. I also replaced the expansion tank with a new one and the upper hose which I managed to damage upon removal.

Everything is great now! Glad it was not the head gasket nor a cracked engine block. It still smells a bit of burnt coolant and probably will for a while.

Feel like I dodged a bullet!

Thanks!

 

You could always hose it down to get rid of the remaining coolant.
Hopefully that's all you have to do for now. My repair turned into a much bigger headache.