Hey Jesse, I'm sure Matt could tell you all about that problem. You're hearing the legendary HLA (hydraulic lash adjuster) clatter. It's caused by the lifters not getting pumped up. Assuming your oil pressure is sufficient, it usually means your oil is a bit too dirty to make it through the tiny ass passages to fill up the lifter.

Solution: change your oil a lot. I do mine every 2000 miles or so. Castrol GTX is the only oil my car likes.

As soon as my car starts clattering on a hot start (cold start will usually do it momentarily even when the oil is fresh), I'll go ahead and change the oil. Cheap way to keep the car happy and healthy.