Got a mechanical cooling fan? Maybe smashin' the accelerator flung a fan blade off. I was mowin' along a few weeks ago in a Massey Ferguson tractor and somethin' went 'whoppity bang' at full throttle and then there was a weird VIBRATION and I could smell anti-freeze. Turns out a blade flew off the cooling fan and chopped through a radiator hose. Haha
Also, a few years back, a friend of mine dumped the clutch as a red light turned green in his little Mustang II and somethin' went 'ka-bang' and it turned out to be a fan blade, which, by the way, went through his radiator and dented his hood. lol Turned out that there was a recall on those cooling fans for his particular car. Haha