so im looking at an XJ with 270k on the body and 127k on a new engine. When i go to look at what should i really be looking for? What are common issues with this kind of mileage? I owned a cherokee before so i know kind of the basics of what to look for already such as rust, axle etc.

 

I would make sure it runs down the highway smoothly and straight. Its expensive to rebuild the front end. Next no check engine light and that it comes on when the ignition is on and engine is not running. Smooth shifting through the gears. Check trans fluid, clean and not burned. no sweet antifreeze smell under the hood or in the cab. AC is also expensive to repair so it should work. No large oil leak at the rear main seal.
Good luck
Ron

 

Someone replaced the engine already- take a good look at the workmanship. Wiring harnesses still neat and attached? no bolts or other parts missing? .... the worst thing to deal with on older cars is often the previous owner's handiwork.