Okay; I raided an '06 S80 2.5T for some parts today at the U-Pull. First of all; I pulled a clearly aftermarket MAF and housing off the car and put it on my XC70. The housing that was on the car was even more clogged than it had appeared when I first looked at it in the airbox, it had dead bugs and ...

I was having similar issues on my '06 and opted to buy a clean, used ETA from the local wrecker for $25. Before mounting it on the car I took the plastic cover off of the side to confirm it had no oil intrusion and that the plastic gear teeth were still intact. That solved my issue.

No fan means no air over the condenser when the car's not in motion means no cooling is going to happen. Plus your pressure's going to go pretty high, I'd imagine. Fix your fan first of all.