my in laws have a 03 caravan with 21,000 miles, yes i know! last week engine started missing and vibrating, took it to the local dealer and they could find no problems. as luck would have it, it started doing it again. i was curious if the thermostat could be sticking? would the dealership had found this during their testing?

 

Mot likely that the thermostat is not at fault. Has the engine check light come on? You need to check it for codes. Could be a number of things, bad sparkplug wire, sticking injector or exhaust recerculation valve.

 

dealership said they pulled no codes. had tires balanced and rotated. seems to be doing this only at slow speeds.

 

I am having a similar problem except my 2003 3.3L caravan has 106,000 miles, trade? I have checked wiring harnesses, cleaned the throttle body, and replaced the coil pack as I did have a code indicating a coil pack issue. Mine started after having the spark plugs, wires, and water pump replaced. Did you ever resolve this?