My check engine lights been on for two weeks and belt noise or nearby has a high pitch screaming noise that hesitates when taking off from a stop. Now water is coming out of heater duct that is under driver seat when using floor vent ! I wish all these problems were related but doubt it.

 

Welcome to the Forum. The water on the floor is more then likely the heater core. How is your coolant level been?

As for the CEL, you need to get that scanned to see what it is. I would do it sooner then later. Would have to see the car to see what the belt noise is.

 

Water coming out the ac vent under the seat Volvo s40 any help please on how to fix this

 

could be one of two things - If you are losing coolant, you probably need to replace the heater core and/or the o-rings. If its just water and you are using the AC, it could be the condensation drain lines are clogged. Either way you need to pull away the carpet and remove the sides to the center console to access.

 

More than likely it's water under the carpet from the sunroof drains.