Occassional rough idle?

My daughter bought a 2004 PT Cruiser, it has 97K on it. It runs down the road very good, but when parked and idling it will run rough for just an instant and will shake the car. Has anyone else had this problem and what's the cure?

Bobg

Yes, My wife's is doing that now, but hers also bucks a little on acceleration. No computer codes. I am thinking it is a loose connection, possibly the spark plug wire.

My wife and I just bought a 2005 PT and are having similar issues. The folks at the dealership told us that it was the 4 cylinder engine trying to keep up with the AC usage. I'm not convinced and the dealership is going to check it for us, but we know how that will turn out. :iceslolan