gotta be something loose. check you heat shield

 

god i had a simialiar story of shaking, especially when i went faster..... I wasnt my main 2 motor mounts........ It was a third mount in the middle (2003 Neon)..... It is jusstantoher mount,fat insert with a plate around the middle with 5 holes for bolts that to screw in. If anyone knows the name of it, i would appreciate it. Anyways I had to special order this thing cause at Oreillys and AutoZone dont carry it in stock..... Well I got it at Oreillys for $58.00 with my friends discount...... but if you wanna ask about it.... the part number was a 2947...........

 

have any pics ?

 

All neons do that

 

I used injector cleaner and added CD2 oil lub and lower the vib a lot.

 

I've noticed this on my wife's02 Neon and I think it has something to do with gas quality. It doesn't happen all the time but at times the idle really drops off to the point where the car shudders. This isNOT normal and the car is very well maintained so I don't believe it is the car. I think at times we are getting water from condensation in the underground tanks where we refuel. This problem only gets worse in the cold weather.I've been running a bottle of HEAT in the car at each fill up and haven't noticed the problem lately. I've also noticed a difference in my Dakota at times and have been running HEAT in it as well. Try some and see if it helps. It's cheap and worth a shot.