o.k. here's what's going on. i'm getting a rough idle when in gear when the engine's hot. when it's cold, the engine idles very smooth & you can hardley feel it run. as the engine starts to warm up, the idle starts to get rougher & rougher. i just recently had the top engine mount replaced because it was collapsed. they changed it from the second design to the first design per the service bulletin. i also had that vibration damper installed per the service bulletin. the other mounts are like new. i was getting vibration at speed from the bad mount, but that's now gone. my steering wheel even shakes a little at idle. what happens is when i come to a stop, it almost feels like the engine's going to stall, but it never does. it's a constant, rough low idle. if i put the car in neutral, it goes away. when i come to a stop, the engine rpm's drop close to just above zero, then pickup a little to a rough idle. the car's a 2001 sc2 & it only has 22,000 miles on it & everythings factory original under the hood other than the battery, that vibration damper, & top mount. any ideas?

well this sounds perfectly normal. saturns are not smooth at idle. over the years it has gotten better. what are the rpms it is idling at and does it bounce a very tiny bit at idle(like 800 up to like 850)?

if its smooth driving, then its just most likely the normal old saturn rumble.