Mitsubishi Repair: metallic rattling sound, mitsubishi 380 vrx, exhaust pipes

Question
I have a mitsubishi 380 vrx v6. On starting from a standing start for about 10 t0 20 secs a metallic rattling noise can be heard by an observer a few metres away. Car has had lifters replaced and oil pump replaced by dealership to try and fix the rattle. the noise still persists.

Answer
Mike,
This one is tough to diagnose without actually hearing the noise and its severity.  But in some case, rattles like this can happen due to loose or damaged exhaust shields.  These shields typically surround the exhaust pipes over large sections of the exhaust system.  Over time, they can become rusty or damaged, causing them to loosen from their bolts.  As the exhaust heats them up, they expand, causing them to tighten up.  But when cold, they can tend to rattle around for a while.  If that has not been checked, do so.  This is something you can actually do yourself, if you don't mind getting a bit dirty.  But only do it when the car has completely cooled to prevent any burns.  
Good luck!