Engine runs and sounds normal but, none of the three belts turn while the engine is running. The belts are the correct belts, the correct tension, and none on the pulleys are stuck or broken. The belts spin slowly or not at all while the engine is on. Car has 127,700 miles on it. What could be causing this issue?

 

Does the crank pulley turn? That is the big pulley at the bottom which should turn with the engine.

If it doesn't turn it is possible that the bolt has come loose and the key is stripped. Usually when that happens the whole thing falls off and lands in the road though.

Also the stock crank pulleys were steel and painted black or possibly gold chromated. If you have some brightly colored aluminum aftermarket POS on there, that could be the problem.

 

The crank pulley does not turn with the engine, but it does turn. It's a stock pulley.

 

You will need to investigate that then. Hopefully the end of the crankshaft is not too chewed up. The easiest way to work on that part is through the wheel well. Jack up the car, support it securely, and remove the tire/wheel. Then remove the plastic fender liner and the crank pulley is right there.

The bolt is standard right hand thread, and it needs to be very tight (140 ft-lb) to avoid coming loose. You will probably need an impact wrench to remove and install it. When you get the bolt out and pull the pulley, there is a little steel key (very easy to lose) which is also important to the situation.