Yes, the engine doesn't turn by hand because the timing chain jumped luckily while I was starting the car and not driving. I was starting the car and suddenly it was like the battery just gave out. A thud/clank every time I turned the key. Upon trying to turn engine by hand I realized that it jumped teeth and that the starter and battery were good. I got scared so I decided to change the timing chain as well in addition to the 3 rails and tensioner. I will get the engine to turn by slowly backing off. I still have to find the post to make sure it's the driver side cam that usually lets the chain slip but I will get it to turn. Btw is it just in NY or the price of a OEM tensioner from dealer is in the $400-$500 range ? This car has only 140K on the engine and the 1988 560SEL before it had 248K on it's engine with original chain and rails. Rails weren't that bad with some grooving but the chain was stretched 2-3 inches if memory serves.