Our “Liberty” is still called a Cherokee in all markets out side of North America. And yes, they are still using the 4.0L in China mostly in what we know as the WJ. The Jeep 4000 has 4.0s and 4700s have 4.7L V8s. Any way, the “Cherokees” over seas pretty much have 2.5L or 2.8L diesels mated with five speed manual as standard options. How I WISH we had this option in the States.
I find it odd your on your 3rd engine. I’ve never herd of any thing like this coming from a Jeep before. I’d take it back and demand they give you another one. I’m assuming your Jeep is a CRD since I saw very few gas Jeeps in the UK the last time I was there.
What was the problem with the other three engines? Maybe its some thing your doing to it? Over rev’ing it, wrong type is fuel maybe? Not saying you have done these things, but just ideas.