Dodge Repair: 3,5L engine will lock up when crank turned 1/2 rotation, crank pulley, center bolt

Question
I have a 2003 dodge intrepid,3.5v6, the engine starts to turn over ( half a revolution ) and then it locks up. Thank you very much for your time

Answer
Hi Richard,
That engine has a drive belt that connects the crankshaft to the cam shafts, and also the 4-valve per cylinder design means that the cam shafts have to rotate in synchrony with the pistons or there will be interference between the tops of the pistons and the valves. My belief is that the timing belt has broken and ideally this happened when you purposely turned it on and tried to start the engine rather than when it was moving at a high rpm because you might have avoided damage to the valves were that the case. There are three covers on the front of the engine which hide from view the timing belt and all the sprockets but the round cast metal cover on the left (driver side) upper corner of the engine may reveal whether the timing belt is indeed broken if you remove the bolts that hold it in place and gently pry the upper edge open a crack so you can look inside at the belt with the aid of a flash light. The other possibility is to look down the oil fill opening which may show the camshaft (I don't know this for sure) and then if that were so you could turn the crank by hand with a socket and a handle on the crank pulley center bolt and observe if the cam rotates in synchrony with your rotateion of the crank. That is a guess on my part.
But my thought is you have a broken timing belt and the engine only rotates so far until a piston strikes a valve.
Please 'rate' my answer (see below).
Thanks,
Roland