I recently bought a 2009 PT Cruiser which now has 38,000 miles on it. When I sit in idle, at a stop light or anywhere else, the car begins to go through a cycle where it is at about .75 RPMS (On the dial) for about 15econds, then all of a sudden I’ll feel my car shake and the RPM’s fall to just below .5 and then it shakes again and kicks up to 1 RPM before settling back down to .75. This cycle repeats until I move. Also, after the first “shake” the AC on my car goes out, spitting out warm air until I begin moving again. (Not good in TEXAS heat) This happens EVERY TIME the car goes through this cycle. WHAT IN THE WORLD IS THIS!!??
i would venture to say the first thing is to get the A/C serviced. It could just be something as simple as an idle control problem due to low refrigerant. You could go to the parts store and get an R-134A service kit. If you do, make sure you at least get one with a gauge so you’ll know when it’s full.