OK, we have to help you... If that heater core had sand in it, trust me, it wouldn't wait over five years to give you trouble. Plus you should have had several routine maintenance services, which would/should have included radiator flushes and oil changes etc.
I'm sure you are upset about the trouble you are having, but it's not fair to blame a Jeep that has not given you trouble until it is considered kinda old now; old enough that it's paid for and out of the regular factory warranty etc.
I'm trying to be kind, but this is not a bad product. 5 to 6 years and no problems is pretty darn good...
This vehicle isn't yet paid for (3 more payments). The heater core is located in the dash, and is expected to be an 8 hour job @ $100+ per hour. It is probably the most serious repair I've ever experienced in a vehicle this new. Mileage is under 50K miles... I'm sorry, but I think that a vehicle should be able to make it just a bit longer without having a major repair such as this.
Thanks for the comments, however, I find it pitiful that we should expect a vehicle to only last 5-6 years without any problems, especially one that has been well-maintained and has only 43k miles.
My other vehicle is an '89 Ford F350 truck, bought used, that has given me less problems in its total lifetime than this single incident with the Jeep. Search online for Jeep Wrangler casting sand, and tons of responses come up. This is a quality control problem, probably stemming from the outsourcing of engines and parts. The six 2004 Jeep Wranglers never gave us a spot of trouble by comparison, and had the same maintenance.
I'm on a budget. It is my policy to buy the best quality I can afford, and take care of it so as to get as much use out of it as I can, so this development is disappointing. Maybe you're better off than I and can afford a new vehicle every few years... I can't, and expect this will be the last new car I ever own, I'm sorry to say.