2006 Pt Cruiser has corrosion around thermostat housing--looks similar to corrosion on a battery except it is pink and flaky. The A/C stopped working about a year ago as well.
Just sounds like the thermostat gasket may have a tiny, tiny pin hole. Probably good Idea to have a new thermostat and gasket put in.
Search Chrysler PT Cruiser Questions
Chrysler PT Cruiser Experts
Kelly Little Ashford