My 00 Chrysler 300m 3.5ho has a minor shaking feeling when at a complete stop but accels fine, but after car has been driven for at least an hour or more turning the car off while going to the store maybe about half an hour to an hour then when starting car up it turns on an 2-4 sec. Then shuts off will do that at least 3 times before starting but as it starts the 3rd time it has a really bad shake an then it will eventually smoothen out to a consistent flow. Not sure what it could be but other then that cold starts, are fine short distance stops an starts a fine it's just when this car drives for long distance.... Parts recently replaced in the last two weeks, oil and filter change, radiator flush and fluid change, thermostat, water pump, a/c belt, input output speed sensor, transmission cooler system replaced, ..... Any help will be greatly appreciated thanks

Sounds like your crack shaft position sensor or cam sensor might be going bad. Has it gotten progressively worse?

When at a stop the shake became a little more noticeable but runs the same, i also changed the spark plugs,... Just changed alternator 4 days ago ever since I did that, car started to make this squealing noise coming from the idler pulley, decided to by a new idler pulley an it's still making noise also tried to tighten the tension still makes noise not sure I tightened it enough ? But thanks for ur help I'll try to change those sensors an see what happens...

Did you change the belt when you changed the alternator? Might be an old belt. Before you start replacing parts try letting the parts house check your computer first to see if you have any codes and if you do then post them.

Okay thanks cause my engine light is not on... But it did turn on right before I changed the speed sensor due to speedometer not working an car was not shifting gears but when changed 2 days later engine light went off, an everything ran fine It's just the shaking and the long distance stops an starts, everything else seems fine