I don't know about the knocking, but my car was much faster on take off after I adjusted the rack dampener pin. If your engine has a lot of vibration at idle this could also be a sign that it needs adjusting or is broken.

If you haven't looked at this yet it's very easy to do, especially if you are handy enough to be contemplating a DIY engine swap!

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...