Early models had soot buildup in the heads, camshafts not pinned which meant timing went off when they did rotate.
Friend has a 2015 JGC with the diesel, spent more time in the dealership trying to fix CEL light vs actually driving the thing.
And try to find a dealership that has a tech that knows what they're doing fixing these things, and if they have a tech, there is a 3 - 5 week backlog on repairs.
Buy gasoline powertrain is my feedback.