Crankwalk? Some symptoms...

[jongreenway]

A while ago, RPM's would drop to about 600-700 at idle, and car would feel like it was going to stall. After the engine mounts were replaced, it was fine. No shaking, but the RPM's would still drop sometimes. It will idle normal at 900, but sometimes drop down to 500 and then back up to 800, then back down to 500. It kind of goes up and down a bit for a while. It hasn't been happening lately after I had the timing belt done. I'm wondering if it's crankwalk... after I've been reading the description and symptoms of it. I'm turning into a bit of a hypocondriac...

 

[eboy0]

Wouldn't jump straight to crankwalk, check your ISC motor(http://www.geocities.com/motorcity/downs/7678/dsmtests.html) my idle bounces around as well, with no boost leaks, my ISC motor is out of spec.
Check that first. Also, does it get less bouncy as your car warms up more/driven for longer period of time?
About it going away after you changed your timing belt, that i don't know what to say about, sorry.