07 manual trans, last night went to do a burnout as I have many times before, stopped because loss of power right after I dropped the clutch, and it's idling weirdly, shut it off and checked codes, got a misfire in cylinder 1, replaced the coil, runs fine again, but then noticed a slight tick near the rear of the engine, not consistent like a cam or anything like that, time between each tick is about 1 to 5 seconds, no idea what it is, anybody else have this problem?