Ignition wire failures can cause a rough idle or intermittent engine misfire and there might not be a Check Engine light.
Average mileage: 56,266 (27,000–85,532)
Engine affected: 4.0L 6 Cylinder
10 people reported this problem
started running rough and would stay running. One dealer couldn't figure it out after 5 days, i towed it to another dealer and finally they noticed a burnt wire. The wires were arching and they replaced two instead of all, now at 38500 it happens again... dealer wants $400 parts/labor for wires, plugs...bought wires/plugs and did on my own.