Its gone 150000 KM (93,205 miles). Would its engine be reliable to last another couple of years? Should I be on the lookout for any noises the engine makes that signal trouble? Thanks
It depends, mainly, on how well the car has been maintained. If it has been looked after, serviced regularly, and had the belts changed at the appropriate intervals, then yes, it should last a lot longer than that - I'd expect to get a good 150,000 miles / 250,000km out of most modern engines without too much trouble.
On the other hand, if it has been neglected, it could fail at any moment...
Assuming that you're answering this because you're looking at buying the car in question, I'd look at any history it has got to see if it has been serviced properly - either garage receipts or receipts for parts if someone has serviced it themselves. Look for general evidence that the car has been looked after - if the bodywork and interior are a grotty mess, chances are it has been neglected. Use such signs as negotiating tools!
Check for any signs of contamination of oil in the coolant or vice versa (although condensation can cause the latter), excessive smoke from the exhaust, excessive oil leaks, any coolant leaks, odd rattles, clonks etc. Make sure it starts happily from cold.
If you buy it and don't know it's provenance (or if it is already yours), give it a full service, including cambelt (if it has one), ancilliary belt(s) plugs, filters, oil & coolant, etc. Check the specialist Jeep forums to find any known weak points on the engine in question - for example some engines need their water pumps replacing at the same time as the cambelt.
Which engine does it have, the 2.5 4.2 or 4.0 straight 6
The 4.0L is one of the most reliable engines out there, however being a jeep it has other problems, the engine is generally the last thing to fail.