Timing chain misaligned
It is possible that the timing chain has stretched over time and skipped a notch and misaligned the timing marks. I would have a technician, from YourMechanic, come out and inspect and install a new timing chain (https://www.yourmechanic.com/services/timing-chain-replacement) and sprockets...
2004 Grand Cherokee Laredo with 176k miles. Periodically shimmies, chugs and shakes when cranking. Takes a few minutes for it to adjust itself, then smooth sailing. Happens intermittently and nothing shows up on mechanic's scanner...
2004 Grand Cherokee Laredo with 176k miles. Periodically shimmies, chugs and shakes when cranking. Takes a few minutes for it to adjust itself, then smooth sailing. Happens intermittently and nothing shows up on mechanic's scanner. Mechanic has cleaned injectors because it was doing a little skip when driving. Last April throttle position sensor and oxygen sensor were replaced and it's happened a few times after that. Mechanic's Assistant: Have you located all of the vehicle's oxygen sensors? Are the wires leading to and from each intact and in good shape? I'll have to ask mechanic. Mechanic's Assistant: Are you fixing your Grand Cherokee yourself? What have you tried so far? No. Local garage. Mechanic has cleaned injectors because it was doing a little skip when driving. Last April throttle position sensor and oxygen sensor were replaced and it's happened a few times after that. Mechanic's Assistant: Anything else you want the Mechanic to know before I connect you? IAC idle motor was replaced recently.