Some background:
Olds 350 rebuilt about 3 yrs ago. Probably about 3000 miles on it. Runs great. I always change the oil at the start of every season. This year I drained the oil and did not add new oil for several days while I did some other work on the car. I added oil and changed the filter. Started the car and within a few minutes noticed a knock. I did run the car around the block a couple times thinking it may be a collapsed lifter. It was not knocking at the end of last year when it was put up for the winter.

what I have checked:
pulled the plug wires 1 at a time to see if the knock stopped on the dead cylinder. It did not stop knocking during this test.
pulled the oil filter back off and drained the oil through a coffee filter. No evidence of metal in the oil.
cut the oil filter in to and inspected the filter element. No metal particles in the filter.
checked the torque converter bolts
removed valve cover on drivers side and checked valve lash. The noise sounded like it was coming from drivers side at rear of the engine.
checked external rotating parts for looseness or interferance.

tomorrow I plan to remove the passengers side valve cover. Any other suggestions would be greatly appreciated.
thx Steve

 

Could a jack have been placed under the oil pan? Inspect the bottom of the oil pan for any depressions that could be contacting the rotating assembly.

 

Thanks for the response but I was under the car today and pan is fine.

 

Check for loose torque converter bolts particularly since the engine was out 3k miles ago.

 

In Park:
Does knock increase in speed (cadence) w/ an increase in RPM?
While driving:
Does knock increase in speed (cadence) w/ an increase in RPM during acceleration?
Does knock decrease in speed (cadence) w/ a decrease in RPM during deceleration?
When you shift into Neutral while driving (at speed) does the knock remain while in neutral? Does the knock decrease in speed as the RPM winds down to idle?