Pinging sound coming from engine

[92BMW318is]

you know those musical triangles that make a dinging noise, it kinda sounds like that. you could say its ticking like a clock but at a irregular rate of speed it doesnt keep a steady pace like a metronome.

here is a image showing where it is loudest.

(I pulled this image off the internet because it is cold out side to take a pic.)

What could it be timing chain tensioner? any IDeas?