Strange engine idle

[digitalis46613]

Been having something weird happening pretty consistently now. Drives and runs fine, but sometimes, after you stop at a traffic light, the engine all of a sudden goes super low idle and shudders a bit.
It only happens once it's stopped, not WHILE stopping, and I noticed it happens when the AC is on or off (thinking it was compressor cycle causing it). It seems to drop to about 500 rpm, for about 2 seconds, then back to normal idle again. It doesn't happen every single time, but I've noticed it seems to happen after a long (20+ minute or more) drive, but not always.
Any ideas?

[zengshengliu]

I have the exact same car as you and same problem as you. Its been doing that since a while back, but ever since they did the recall (to lower idling RPM), it make it more noticeable. I bought it to the dealer multiple times but they said they couldn't find any issue. And the strange thing is, it only happen when you first come to a stop, but not while stopping. Also, it doesn't happen all the time, and is temperature independent. It also happen only when the engine is fully warm up.

[digitalis46613]

Yup.. That's pretty much it. And it doesn't happen every day either. Any one else have any experience with this?

[Big Red Rogue]

The same thing used to happen in my PT Cruiser every couple of years when running the air or defrost (anything that ran the compressor). Replace the fan on the radiator and it was good to go.