Engine rattle -> loose component

[fawtytoo]

During a rare engine detail session, I found this, erm, what-ever-it-is loose. This is on the left side of the engine. There's an empty bolt hole that looks suspiciously where it should be.

What is this thingemy-jig? There looks like only one wire to it.

[Carolyn]

It should be bolted to the cylinder head.

[Joesson]

@fawtytoo


As C said:

[fawtytoo]

Thanks guys & gals.

Can you enlighten me as to what it does? It looks like maybe a resistor/filter.