I'm good with Kool-Aid, after all I'm still not turned off of Jeeps despite my XJ rusting and half and poured WAY too much time into VWs
I am concerned that you guys both mentioned the likelihood of a busted exhaust valve. I did some research on the broken rocker issue, that doesn't sound like TOO much of a pain in the arse to deal with. I can take a gamble but any serious chance of needing to replace the head would make this purchase impractical.
From what I remember reading the Timing Belt How-To, pulling injectors doesn't seem like it would be too much of a hassle. It looks as though they're pretty easy to access just by pulling the plastic engine cover off. Is there enough protrusion into the cylinder that this would be a realistic way to gauge if a valve is smashing around inside? If so, how long could one expect that job to take? It looks like I'd just need standard tools, standard encouraging vocabulary, and penetrating oil to get them out. Does this engine have one-time-use copper washers or cups that I should be concerned about if I'm just inspecting the injectors?
So, the extra information: Maintenance-wise the owner seems to be very conscious of the requirements. He commented that he refused to take the Jeep to the local dealership if he could avoid it since they literally only sold three CRDs and the techs were idiots. Exactly where he took it I don't recall, I think it was either a truck shop or a garage where they work on other diesels. Not a ton of diesels that aren't VWs here sport timing belts, however. It is in the middle of its second timing belt, so from what I can tell it is possible that it wasn't tightened properly and I guess could have slipped a tooth? Even though it hasn't hit it's mileage limit, the vehicle is 13 years old, so that belt could have been put on in 2010...
The other thing I was thinking about is that this guy really babied it. He kept boasting about how long his tires and brakes last and what good shape it's in. Which is great, except for "driving like a grandma": He relayed that he got laughed at by a mechanic when he brought it in reporting a lot of black smoke when he had to pass someone on the highway, as he normally is "very gentle".
I read on here that these things are programmed with a seriously aggressive EGR. It occurs to me this could have been caused by a chunk of broken off soot. The part of highway he was on when this happened is around the crest of a hill, so engine would have gone from under load to deceleration right before whatever broke broke. If I understand how the FCV works, I'm guessing that change in pressure in the intake combined with the flap moving about could have done broken a chunk free.
I really appreciate the suggestions. I realize that the only way to be sure is to tear it down, but this Jeep is sitting in some guy's driveway an hour and a half away
Thanks!