Bizarre Heat Issue

I have a strange heating issue with my 2004 maxima. When driving, the heat works perfectly fine. However, if the vehicle stops such as at a red light or stop sign, the air almost instantly becomes freezing cold. Also, sometimes when accelerating from a stop, I can hear a sound on the passenger side like flowing water. However, I can remember hearing this noise from the first day I bought the car so I always just thought it was normal. I was told that this sound could be related to the heating issue though. Does anyone know what the problem could be here? Could it just be that a new engine thermostat is needed? Thanks for any help.

I have a strange heating issue with my 2004 maxima. When driving, the heat works perfectly fine. However, if the vehicle stops such as at a red light or stop sign, the air almost instantly becomes freezing cold. Also, sometimes when accelerating from a stop, I can hear a sound on the passenger side like flowing water. However, I can remember hearing this noise from the first day I bought the car so I always just thought it was normal. I was told that this sound could be related to the heating issue though. Does anyone know what the problem could be here? Could it just be that a new engine thermostat is needed? Thanks for any help.

Sounds like air in the cooling system ! to remove get vehicle to operating temp park on a hill so front of motor is higher than rear or raise front of vehicle on jacks open the radiator cap carefully as it will be very hot slowly add coolant to radiator add very slowly as cold coolant can cause problems if added too fast. or you can vaccume bleed the system if you have one available
perhaps check you dont have a small leak at the water pump.

Sounds like air....

definitely. Air means low coolant... There is a leak if coolant goes low, seek & repair... You should have warranty. Dont drive until coolant level is up, bubbles bled, flow corrected.