For most people, a vehicle is a consumer good, like a television or home appliance, and one must evaluate the repair/replace decision solely on the basis of repair costs versus replacement cost. Any money paid is going to be using after-tax dollars, and there are no tax write-offs for a vehicle which is used for general household purposes.
If a person “works for” Uber, Lyft, Door Dash, etc, they are an independent contractor for tax purposes, and can write off for tax purposes the repairs and upkeep on the vehicle used for this “job”. Because of this fact, it would make sense to crunch the numbers using estimated 1099 income and estimated vehicle repair/upkeep costs for the year to see if writing this off will result in a large enough tax savings to make it worthwhile.
Assuming that the math makes sense, I would find out exactly what the proposed repairs entail. Given that the problem has likely resulted in metal shavings getting into the oil, and being circulated throughout the engine, only a full rebuild or replacement with a different engine (used or remanufactured) is likely to result in long-term reliability. Simply replacing the damaged parts is unlikely to result in an engine that will run properly for very long.
Assuming that the math does not make sense–meaning that even taking into account any tax benefits of paying this expense, the cost delta between “repair” and “replace” is small or negative, I’d get rid of it and buy something else. In today’s inflated used car market, it should be possible to sell the Jeep “as-is” on Craigslist as a mechanic special for at least $1500-2000.