Thought I would share this with all you neon owners that are suffering from the rough idle situation. I did everything I could to get rid of the rough idle including changing the motor mounts (all of them) and raising the idle through the back stop but now I think I have finally found the reason for the vibration and it only take 5 mins to do and you can do this yourself and no I'm not selling the idea I'm gonna let you know right here right now ! I just got back from autozone and I backed off the motor mount bolts so they are not to tight and waalaaa it idles smooth now. I loosened all of them and gonna ride around for awhile to let them settle in then tighten each one to try and isolate the bad one. I think it's the top one that gives off the most vibration . I hope this helps you people out and hope it helps try it and see.........

 

PS I know for sure now that it has nothing to do with the idle speed because it's coming down to 550 and no vibration ! Got my gas mileage back too by adjusting the back stop that I increased to see if it was the idle speed but now I know for sure it's not the idle speed. BTW can someone tell me the way to make sure the TPS is putting out 5 volts? And how do you check it if anyone has pics please post link in here thanks.....

 

the motor mount bolts need to be torqued to about 87 lbs so riding around with them loose could cause damage. your motor is still vibrating just as much as always just not transferring as much to the body since theyre loose.

 

I didn't loosen the bolts holding the mount on from the inside, I'm talking about the one from outside the wheel well. I just backed it off a bit and waalaa it's running smooth as silk now and this is proof it has nothing to do with the rpm or idle at all it's smooth as silk now. I'll check it every now and then but I'm gonna stick with this I can't take the vibrations anymore. Again you don't loosen it all the way just back it off a bit and it smooths out.

 

If you do this make sure you check your bolts every now and then. I have since re tightened them and it's still not to bad at all i guess it has settled in now. But like i said if you do this make sure it's just a bit and check it every couple of days to make sure they are not coming out because it's not a good idea to drive around with loose motor mount bolts but like I said before it seems to have settled in and I have tighten them all the way now !

 

I've tried this, along with replacing the balancer/damper, got a tune up with new plugs and wires. all mounts all good, and i still have vibrations, almost like not getting enough air or gas, when I idle at a light or stop sign. doesn't matter what gear it is in, either. But as soon as I give any little bit of gas to it, it rides smooth as a brand new car! 5 mechanics have told me they have NO idea what is wrong with it. they see nothing wrong, and do not think it's in the motor.

My dashboard shakes like crazy, and only happens when I am not accelerating. What else could it be??? Please help. It only has 56k miles on it and is an 05.

 

I did find the hose going to the idle motor had a leak in it. Make sure you look at all the vacuum hoses real good maybe that's your problem they do tend to rub together and cause a leak.