This is a video of the engine in the '90 BMW 325i that we've raced in the 24Hrs of LeMons.

It really should just be an audio clip, but you can check out the valve cover while you listen.

Listen for slightly odd clicky clacky sound. It's most obvious when revving towards the end of the video, but if you listen closely you can hear it earlier on as well.

We were torn on diagnosis between rod knock, valve train issues (many thought it was a rocker arm), or piston slap. When we pulled the cylinder #6 bearing, it was clearly bad adam.lazur.org/gallery/v/lemons/rod-bearings/