Remanufactured Engine with only 4k miles. When first started it's as quiet as a church mouse. After warming up or revving it has a bottom end knock. No oil consumption. Started hearing what sounded like a loose heat sheild about a thousand miles ago on decel and light pedal pressure. Now once warm or revving it sounds like knocking from the bottom front. Since theres no knock at initial startup can I save this engine?

Thanks Alot,

Mrcln1