I'm sure it happens. No machine success rate is 100%. It's just not common in the 4.0L platform. Sorry to hear about yours, mostly I see cavitation from improper maintenance such as infrequent cooling system flushes or another overheating problem due to another component failing. Glad you got it sorted out.A few months ago, I had a check engine light that showed a misfire in #6 with a "shudder" at start up. Then, after about 15 seconds, engine would smooth out. I changed the plugs, fuel injectors, full fuel system cleaning and also read a bunch of stuff about the cylinder 6 issues. My mechanic took a camera and ran it down cylinder 6 and saw the cylinder wall was soaked in coolant. From what I read, it was an issue with the head gasket material (guys, please correct me if I'm wrong). After tear down, the condition of the old head gasket showed evidence of overheating at some point before I bought it. The new head gasket material looked much different.