check the motor mounts
I Assume Your Town Car has 4.6 Engine Either way Sounds Like Coil Pack Is Going Bad Have A Dealer Check it ......:)
Sounds like a very weak battery.
if your alternator is gone or going your car will start and then eventually just stop running because your battery has gone dead. it typically will not make any sound when your engine is not running because of a dead battery.
Usually vehicle just stops running with no warning
sounds like the fuel pressure regulator, which is made into the fuel pump in the tank of most new cars and truck, or you could have dirt in the fuel line, first change the fuel filter, and see if this helps. Need to know if the starter works and cranks the engine but the engine doesn't start at times or if the starter doesn't crank the engine at times. It is not clear.
probabaly a knock sensor going off
what if he gas is going to the engine but the car want start?
need more info on that one. what sound can you hear when trying to start, if engine is not turning over.
when it wont start or when something sounds funny
Not really as long as you have the correct size 12 volt battery the CCA rating will not effect the batteries initial ability to start the engine. It may not be able to turn the engine over as long as a higher rated battery but it will start the engine if all is as it should be. A sluggish start sounds like you may have a starter going bad.
When you accelerate. you are putting presure on the main engine barrens. if they are going bad. You will hear this knocking sound. I don't know how many miles you have on this engine. But that's what it sounds like. But that's not all that can make this sound. You will have to tell more about it and when it started. Did it just start all at once? or did it start and then get louder?
it sounds like the timing
It sounds like what is called the cold start solenoid going bad
Clean the battery cables first.
It sounds like no spark on your plugs check the power going to your coil if you have that then it could be the ignition module under the rotor,assuming you do have gas in it :)
Sounds like you need a new starter!
Sounds like a Fuel Problem to me.