Yea, I'm a freak..
I started up my car this morning and instantly it started making this "clanking" noise. After a few minutes the sound went away while the engine was at lower RPM's but would reappear above 2500 rpms. After about 5min total the "clanking" sound went away and I never heard it again on my 40 mile trip to work. I'm wondering if me starting my car up for a brief minute just to move it a few feet was the cause of this. Anyone else have this happen?