Second time it has happened.... Go out in the morning, start the beast up and right at cold start up, she really knocks and rattles for about 10 seconds and then smoothes out and runs fine... NEVER done this before and it has happened twice in two weeks. This does not sound like an HG problem but more like a rod or something? Could it be the starter making all that noise? It was replaced about 40K ago. HELP, almighty mudders! Jeb EDIT: UPDATE: Just went out after it idled for about 5 minutes to warm up. There is very noticeable rattling/knocking, yet quieter than the start up noise, coming from somewhere around the front of the engine from inside from what I can tell. Definitly not the starter.