: Look for water damage on the interior roof or floorboards, indicating leaking seals. Reliability by Generation Generation Key Focus Areas YJ 1986–1995 Frame rust at shackle mounts, 4-cylinder power limitations. TJ 1997–2006

: Use a flashlight to check the engine "valley" below the oil filter for oil residue from a potentially failing oil cooler housing. Check for radiator and thermostat housing leaks.

: Inspect the skid plates, differential covers, and transfer case for deep gouges, heavy scrapes, or signs of frequent mud bogging.

“If you can pull rust chunks out of the frame [on a TJ], then you should do either a frame repair or a frame swap.” Jeep Wrangler TJ Forum · 7 years ago What To Look For When Buying A Used Jeep Wrangler!!

TIPM electrical failures (2007–2010), oil cooler leaks (2012+), heater core issues.