If it was the timing chain, you'd know it, and it would happen any time the engine was running - not just when it is cold.
How many miles are on the car? I assume you've checked your oil level?
Blue-ish 2006 2.4, Werks stage 1 turbo, GMPP cat-back, TCE Wilwood 6 piston front brakes, 4-piston rears , Stainless brake lines, slotted and drilled rotors, DDM braces, BR Racing coilovers, Spec aluminum flywheel, Spec stage 2 clutch, Werks aluminum radiator, DDM oil catch can, Autometer boost, water and AFR gauges, RKSport hood, Morimoto FX-R HID headlights, GReddy Profec boost controller @ 13PSI, custom A-pillar gauge pod.
In progress: custom fiberglass trunk lid.
Currently on engine #4!