I bought an off-lease 1997 F150 with the horrible 4.2L V6 and 5 speed transmission, short bed 4x4. I twas a fun little truck to drive.
At the time of sale I was talked into the extended warranty (it was my first newish vehicle). It had something like 30K on it and at 69K the engine started using coolant and steaming after start up. They were known for timing chain cover leaks, intake gasket and head gasket issues.
No dealer would touch it, even though I was covered by a Ford extended warranty up to 75K. They kept pushing me out of the door saying they could not locate the coolant leak. I think they hoped it would make the last 6,000 miles. Finally after a very hard start and coolant pouring from the tail pipe, I got the selling dealer to do something about it. On a Saturday afternoon, I pulled it up (not daring to shut it off) to the glass showroom windows and talked to the service adviser. While talking, it was steaming and leaking antifreeze from the exhaust. After being rejected again I told them I'll be leaving right there out front for the customers to see and smell. The service manager pulled the owner and parts manager aside and suddenly I was offered a very high trade in value for a truck on the lot. I happily accepted and picked a nice little black one that was out front.
Not surprising, I did not opt for the extended warranty.