[Cal Cruzer]

Originally Posted by NewPTCruiserInPA

And now, to top it all off, when the car is in idle it blows hot air! When you are driving it blows cold. At least BEFORE we took it in to get looked at it blew cold air in idle! So every time you come to a stop sign it blows hot, then cold in drive, then hot when you stop again.

It could be a couple of things.
1. It may be idling to low to spin the compressor fast enough to circulate the freon. I would really recommend doing the wires and plugs. This is such a common thread with most PT owners that it is the first thing we jump on.

2. Just because they replaced the compressor doesn't mean they found the leak. If they didn't perform a dye test (introducing dye into the system that shows up under black light at the leaking points after the system has been run) then you may still be leaking at a hose or connection.


Your cars computer is programmed to raise the idle when the AC turns on. There is more drag in the engine when the AC clutch engages and this is supposed to compenstate. If your freon is low, you have a pressure switch that automatically switches the compressor back off so it doesn't burn it up. You could be in this constant loop of having just enough pressure to turn the system on, having the computer see that and bump the idle then the pressure switch turns it off again etc, etc, etc. At speed the system may be turning fast enough to keep the pressure up and the compressor running. Even though the computer can react quickly enough the mechanical part (the engine) just doesn't respond that quickly at idle.