broke down

If this motor is 4.0 Single Overhead Cam, you have timing chain tensioner problems. Engine has to be removed from vehicle for replacement. Has two timing chains in front and one in rear. You will probably need a new engine.

there are guides on the chain that break. when this happens, it changes the tining, sounds like it has changed the timing so much it will not run. expensive to replace. need chains, guides and gaskets. pays around 11.5 hours as the motor has to be removed to gain acess Roy

My 2 cents - the 4.0L SOHC engines that had the problem were like..96 - 2000. By 2004, there should be no tensioner or guide issues really. However, your concern is consistant with what Roy is stating. Definitely have your vehicle assessed first.