After driving in heavy rain for a few hours, with the defrost blowing (so AC is on), I notice that the carpet in the passenger footwell is wet with water (not coolant or anything else). This has happened a few times before. I pulled off all the trim, and pulled up the front carpeting (having to cut it around where the seat bolts through it) in order to dry it out.

I've checked the sunroof drains, and they are clear. There is no damage to the floor or anything else visible. In fact, the water appears to be dripping down from the front, that is, from near the firewall or down through the heating core or the air filtration system. I think this because when I finally stopped and looked, the water appear to be dripping onto the carpeting, and then soaking into it, rather than coming up through it.

So, my question is what is up there that could be causing it? What's the solution? I don't want to take the car apart each time after driving in the rain to dry it out.

 

Same problem here. Does anyone know if there is a drain tube for condensation that may need cleaning or replacing?

 

Prior to buying my 2009 S60 I had a 1997 Ford Thunderbird. I had a similar problem with the Thunderbird. Water was collecting in the passengers side rear footwell. Just pure water, no coolant, dirt, nothing. And it was only wet in the footwell, no where else.

Turned out the problem was the evaporator for the air conditioning. It wasn't plugged or anything, just leaking water where it should not be. The leaking water was then finding it's way from the front of the car through all the grooves in the car body to it's final resting place in the passengers rear footwell.

I had to have the evaporator replaced. Suspect you have a similar issue.

 

Thanks for the info. I hope it doesn't come to that. I found this thread on another forum and think they may have the most probable cause:

http://www.volvo-forums.com/t33673-2...r-footwell.htm