Hello everyone, I bought a 2006 civic LX 20 days ago. Today when I turned the engine on, I felt abnormal vibration in the steering wheel. The vibration is like a wave moving back and forth from left to right or the opposite, and it lasted for a few seconds. Is that a symptom of a problem in firing? ( I replaced spark plugs 2 weeks ago ). Has any body had it before?

Another problem (as in the title)is that I heard an abnormal noise from the front-passenger side of the engine, somewhere near the alternator or below it. It is like a metal-hitting noise. Has anybody had this too before ?

Thank you