What is the noise - Ford Escort

[beccyb35]

I have a P reg for escort, it has started making a loud banging noise when I start it up, almost like something rotating is banging against something. the noise seems to ease when I rev the engine - to a sort of flapping?

[Skids]

My sister's Escort did that when one of the con-rods broke. Half was still attached to the piston and the other half was flapping about on the crank shaft. Eventually it smashed a hole through the side of the engine block.