Noon here. Just got an 02 hatchback wrx and noticed some things that don't seem right. First, when I start it up after it's been sitting for a few hours it has a loud knocking sound, but it goes away after about a mile of driving. Also when I'm sitting with the engine on and in park it will start to shake a little, and only in park. The car has a brandnew timing belt and water pump. The only thing wrong that I know of is the CEL that gets thrown from my tumble valve.