Re: Engine knock

Posted by Packard Don On 2019/1/26 3:39:18

Although it sounds like a different type of problem on your car, I'll share this in case anyone else has something similar.

My 1951 Henney-Packard with the 5-main 327 had an odd knocking sound from time to time that was finally diagnosed as rod alignment. The bearings and wrist pins and all hydraulic lifters were checked several times yet the sound persisted and mainly at idle but would go away as soon as the engine was revved up just a bit. It was a heavier sound, more like a rod or bearing knock than a lifter tap but checking the rods themselves it was discovered that one was slightly non-symmetrical when laid down onto a flat surface so a simple replacement of that one got rid of the sound. Later I saw reference to this (which is where I saw the term "rod alignment") either in a Service Counselor or perhaps in a Motors manual.