That is inconclusive for me to hear off the video to say it is a rod or rod bad bearing. I would think it would be a harder knock. But anycase, I would dig into the engine a little bit. First off, find out which cylinder is making the noise. Crack open each of the injectors at the line one at a time. If the noise goes away, then you found the problem cylinder.(keep in mind it will still run rough) I wouldn’t dismiss a troublesome injector just yet. You might want to swap an injector with another one from a good running cylinder to see if noise follows to the new place. Also, remove the valve cover to and check on the valve lash adjustment. It might be a tight valve caused by the adjuster lock nut to come loose.

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1983 123.133 California
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