Got a 2000 Neon at 97K sttill in good running condition. After driving awhile & coming to stops, rough idling & like almost the engine dying on me becomes apparent almost all the time. I had to put the gear in neutral to alleviate the problem. Then put it back in gear (drive) to move on. Got no problem when the car's moving. Only during stops. Funny thing is I laso found out that if I turn on the airconditioning, the rough idling & engine vibration seem to be not happening. Had it tuned up from spark plugs,ignition wires,oil change,PCV valve,air filter,tranny oil,engine & tranny mounts,etc... Haven't touched the oxygen sensors & ignition coil yet. Did try cleaning the throttle body also though I'm not really sure if I did it right. No check engine light lighting up also. Thinking it could be a sensor or something electronic-related. Haven't gone through an OBDII scanner yet but am quite sure it won't read anything wrong. Any advice would be appreciated. Thanks all.

 

How dramatic, because it is normal for the engine to drop in RPM while in gear at a stop.

 

The drop in rpm is totally annoying like the engine vibrating & almost dying. Nothing normal there I'm sure. Just did some cleaning of the map sensor,throttle position sensor & IAC but problem's still there. Did notice some improvement in the acceleration though. Anything else I might consider checking? Many thanks.

 

I'd give the upper and lower torque struts a quick once over. Those are the engine mounts on the passenger side of the engine, and not the one in the center of the engine.

They look like little arms holding the engine to the frame. If you see the any of the rubber torn, it should be a pretty good indication of your vibration.

 

I had rough idle and it was driving me crazy..
I brought it to the shop and the mechanic said that I could clean the engine.. but he also said there was a computer update that could fix the issue. (I guess the update changes the rpm when it's idle..)
He wanted 100$ for that.. and I didn't do it..

But I found that if you put the A/C on, the engine rpm get higher to compensate and then there is no rough idle.
Of course, that won't help during the winter...

Not sure if it's the same thing you are having since you have a dodge 2000.. but you could check if there is a computer update too for your car..

Edit : I just read all your message.. I guess you have the same condition as I have.
If you do the computer update and it works, let me know and I'll do it too

 

There is a computer update for the early 2003's (I don't recall any other years needing it). My condition worsens when I turn the A/C on. I'm pretty sure my car needs the computer update though, especially since it was built very early on; August 2002.

 

Dealership's asking for $150 just to update the PCM computer. They won't even tell me beforehand if there really are any updates for my 00 Neon. They said they won't know until they check out the car. Updates or no updates, they said it's still gonna cost me $150. Whew!

 

$150 and it probably takes them 5 minutes to do it..
But I Think it's one of those thing you have to do at a dealership,
right darthroush ?
Only dodge dealership have the updates ?

 

No, they can run your VIN in their computer and check before they do ANY work. That's a bunch of bull. Dealerships however, are not the only ones that can do the updates. A shop that has the Dodge DRBIII scantool can do them too. A shop around here told me ~$100 for the update, which is also what the dealer told me when they were still around.

 

Yeah, but it takes them a little more than 5 minutes and the software for the updates are very expensive for the shop.