Believe it or not, the factory original water pump impellers on the Ford 6.0L, 6.4L, and 6.7L diesel engines are made of plastic. While this may not seem like a big deal, when this plastic impeller fails, it is highly likely that the engine will overheat which could lead to much more serious engine damage. Bullet Proof Diesel offers upgrades for the problematic factory water pumps for the 6.0L, 6.4L and 6.7L Power Stroke engines.