On a factory new engine the only human side fault that I can see is dirt. Which plays a huge role, bearings beings installed backwards or wrong size bearings which should be just about impossible on a new engine. Improper torque, or improper manufacturing of new parts. The 3.7 I'm swapping out of my car to put in an unknown 5.0. Does tick or as some call it knock at startup, but the noise do go away once the engine reaches op temps. Thats normal with todays engines coupled with todays oils. I'm hoping that it will be the case with the 5.0 I'm installing as soon as I get all the necessary parts for the swap. The guy I bought it from said it sounds awful at startup, but quiets down once at op temps. I believe 5w oils is to thin for startups at min it should be 10w, just my 2 cents. Anyhow on you acquiring a list from your service manager that would be great it gives reasons, maybe not specific but a place to start with none the less. Most guys at work do the parts replacement as you call it. I can't, I left that dept do to how its ran and the issues their having. They are trying to get me back cause of the way I do work. Not the crazy way!!! Oh and I understand the physics of the engine and how a crank flexes with the rod impulses, but the sound is different that being a crank knock to a rod knock more consistent and usually from what I've seen at lest doesn't change during a cylinder load test as where a rod knock sound does. Thats what I like to find out has this been done? There seams to be little trouble shooting in todays market and its understandable to a point the customer wants their car back asap, but without the opportunity to troubleshoot no conclusions will be had.
Last edited by rob47v; 01-05-2015 at 12:04 PM.