1995 Jeep Wrangler SE, purchased new. Last year for the square headlights. 4 cyl, 5 speed.
One morning, I started the Jeep to go to work. While it idled, I heard a knocking that was reminiscent of an idling diesel engine. There was barely 1K miles on the odometer. The interior still smelled new.
Took it to the selling dealer's service dept. They couldn't have been more welcoming.
Diagnosis: "Piston slap". The cylinders were not bored correctly at the factory, which allowed for lateral piston movement.
Treatment: Replace short block.
One week later, I returned the rental car to pick up the Jeep. (Said rental was fully comped by the dealer.) The Wrangler started and ran fine. One of the interior wheel wells was rather scratched up. Oh well.
'Bout 1.5K miles later, the now-recognizable piston slap sound manifested itself again. Took it to the selling dealer's service dept. They couldn't have been more dismissive. At the time, I had neither the time nor the money (and I would have needed both) necessary to fight with them regarding a second short block or even a prorated buy-back. A professional, if strongly-worded letter to Corporate explaining the issue did not provide any satisfaction.
Long story longer: I held on to the Jeep for a few more months, and sold it to another dealership (in another part of the State) for ~$600.00 more than I owed on the note. They had time to test drive the vehicle and run the VIN (I don't know if they took the latter action), so I didn't say much beyond, "Do you want to buy it?" At the time, Wranglers were red hot sellers and dealers couldn't keep them on the lot. Mine was in as-new condition, at least aesthetically. Sold!
There was too much MOPAR in the Wrangler then, and there's too much of it in today's version (which gets more pussified with the introduction of each subsequent generation.)