it's not raining or is it?!
 

I'm leaving the gym and i get into my car... I turn it on and i begin to hear a water flowing sound coming from the front of the car... like in the upper dash area... Has anybody experienced this or have any clues on it?

your car is performing the rain dance

thankfully no.. but it sounds like you are hearing antifreeze going through the heater core... i have no idea why.. Is the antifreeze low?

^either that or you might have an air bubble in the system.

Have you recently had your coolant system flushed/refilled? I had this when I first bought my car right after they had performed a 30,000 mile service to it. The noise is caused by air in the system. There is a bleeder screw on the left side of the engine bay back towards the firewall. I think it might be on a hose going to the heater core, but I'm not sure. There is a process to bleed the air out and I will post it up if I can find it. The noise stopped completely once I did this.

Here is the .pdf that I used. Page 11 shows the process for refilling your coolant. You basically just need to remove the air relief plug and pour in antifreeze until it is full. You can cycle the engine through a few warm ups/cool downs to make sure all of the air is out.

http://www.g35frenzy.com/downloads/2...anual/B/co.pdf

definetly air in the heater core.

If you use the bleeder valve and open it really slow after you warm up the engine you'll get air to hiss out. When the air stops and just coolant is coming out close the valve.

Might have to do this a couple times, but no need to flush the system.

Problem I've had doing other methods is that the coolant spills all over the place. all the time. I've had much better luck simply using the bleeder valve when the car is hot...just let it sit for a couple minutes so the air can work its way to the top.

I noticed this the other day in my sisters 96 Subaru Outback. I thought wtf..

There is definitely no need to flush the system. I did it while my car was cool. Just unscrewed the bleeder valve and added coolant through the radiator until it barely started to overflow through the bleeder valve opening. I don't think mine had much air because it didn't take much at all to stop the noise.

if u smell coolant then your heatercore is leaking

wow that use to happen to my old diamante .. lol

I wouldn't worry about it if it only happens occasionally. My 03 has done it maybe 5 times over the past 5 years. The coolant has never been changed, the car has been hot lapped at the drag strip, auto-xd, and has lived thru numerous Midwest summers without any signs of overheating.