OK., so this is only on cold start that I get this temporary rattle for about 3 seconds, then all sounds fine. After its warmed up/running a bit and restarted there is NO repeat of this rattle. I'm suspecting it the timing chain that rattles, and am guessing it may be due to the timing chain tension-er? Does anyone know if they are oil pressured to tension the chain? It's about a 30 hour job to get a tension-er replaced (no small feat) !!! Has anyone had any experience here?