My 2005 Neon SXT with 69,000 has just devoloped a problem. Twice when driving (once on the freeway and once on a 40 mile an hour road,) it just starts to shutter and you can here a thump underneath. You can't get much more than 35 miles an hour. I pulled off the road and put the trans in neutral and the engines seems to rev just find. If you then put it into drive, it still has the problem. The 2 times this has happened the orange engine icon lights up. Also if I turn off the engine, the problem is cleared up but the light stays on (turns off after a while, maybe 150 miles or so.)

It was just in the Dealership for a trans- leak (I think they said it was around the pump.) I'm taking it back but was hoping to be armed with some information when I do. It has 3,000 miles left on it's extended warranty.

 

Sounds like it may be running rich and that "thump" would be the cat burning off the extra gas. Have em' check the O2 sensors or the PCM/ECU. I'm getting a very small shudder at 2Krpm and part throttle but I think it's just a dead spot in the FI/TB, kind of like being between jets in an old school carb engine. Still, I'm going to keep my eye on it. Good luck and keep us posted as to what it turns out to be.

 

In turned out to be the crank sensor, according to the dealer. We shall see!

 

Glad they got it figured out. I'm still kind of new wrenchin' on these "new fangled" computered controled cars. Old School stuff I know, new school stuff, well, I'm learning. LOL.