The other day as i was driving I noticed a water sound coming from behind the passenger side as I accelerated. Anyone else have this or better yet know what it is. It's cause no harm nor is there any water anywhere. Just strange.

 

most likely water from your AC condenser

 

In 30º weather?

 

Rainwater leaking into the battery box or other crannies?

BTW, doesn't the AC run when your HVAC is in Auto mode?

Spridget

 

At least in my 08 it does.. I always just shut it off

 

Sounds like you have some air in the coolant system. Top off with BMW/MINI brand coolant and idle the car with the heat on full. The bleed screw is on top of the thermostat.

 

+1. bthayer23 is correct; this is almost always the problem that causes the "waterfall noise" behind the dash.

The low coolant level might be due to a leak somewhere in the system. Alternatively, if it was recently flushed and filled the person who did it might not have bled the system properly (has happened to me twice).

 

Funny I noticed the same thing, happens when I have been idling for a while (it goes away when I rev up).
Sounds like its right behind the dash board, like a big slosh of water in a bucket. I had noticed I was a little low on water but I just topped it off.
Is there instructions anywhere on how to bleed the system?

 

It's easy and fairly universal for all cars. Basically, you fill the reservoir to max and loosen the bleed screw. Ideally they're usually at the same height; otherwise, just loose the bleed screw till fluid comes out. The bleed screw for the R56 is on top of the thermostat; for the R53 there's two: a little one on the thermostat and a big plastic Phillips head screw on the hose running over the top of the radiator.

It's also a good idea to open up all the coolant circuits in case there's trapped air there, so you have to open the thermostat and the heater core. Do this by driving or idling the car till the water comes up to temperature, and run the heater at max.

And yes, if you have air, 99 times out of a 100, you have a leak somewhere.