Ford has had some major issues with its engines over the years, including the Ford Pinto or the Edsel brand. However, these engines have become so unreliable that they effectively define the cars they were in. These include the 5.4-liter Triton V8, which has a poorly-designed timing system that can cause problems with the valvetrain and pistons operating in the same space inside the engine. The EcoBoosts have been criticized for their lack of maintenance and the time and effort required to diagnose and replace these belts, making it a costly task. The 5.3L Power Stroke V6 was recalled for faulty oil pumps, adding to a long list of potential failure points. The most versatile engine on this list is the 3.5-gen V6, which was designed to perform well in multiple configurations and has been recalled multiple times.