Hi I have an S60 2.4 diesel from 2002. I've had it since new and its done around 110k miles. Last week during our April heatwave the aircon started to make a strange hissing/squeaking high pitched sound from the vents. Since then it will not cool down so the air is now coming in at a warm temperature. Is this just a recharge job that i can get done locally or does it sound more sinister?

 

that hissing sound indicates a major leak in the evaporator, thus recharging it is going to be money wasted.

Take it to a AC repair shop to do a leak test and confirm the diagnosis.

 

I'm taking to a company called AVACS tomorrow. It's more of a burbling noise than hissing on a second listen and it only happens when the low temps are selected.