[Joel_L]

The have been several posts on "what is this noise/knock". I've read many answers, lifters, thrust bearing, crank/rod bearings, flexplate.... I have a new possibility to consider as you are trying to hunt some of these noises down. I had the "opportunity" to tear down my 289 recently and found that a few of my pistons were very stuck on their wrist pins. This should cause the pistons to slap the cylinder walls as things go around. From what I saw on my piston skirts and cylinders, this was indeed happening. Fortunately for me everything is still serviceable.

FYI

[axman61]

Also on Fords a broken and missing piston skirt will cause a 'knock' without any loss of oil pressure. I've got an old F series with a 4.9 six and that thing sounds like the pistons are swapping holes but it runs fine.