I bought my 1998 Ford Explorer XLT brand new from the dealer, and it gave me many good years. About 3 years ago, though, it began giving me issues. I ended up consistently putting money into it nearly every month. Honestly, the body began to go before the engine did... but once the little things started going wrong, it added up very quickly. The last thing to happen was a cracked thermostat housing, once I fixed that, I sold the truck.
I really loved my Explorer, would recommend one, and bought a new one after selling my 1998. It did have awful gas mileage, my 2009 gets better mileage than my 1998 ever did.