Another question - engine noise...
 

Just recently got my 1999 328i. It drives awesome and has TONS of power. However, my engine makes a noise that sounds like two pieces of metal rubbing each other at all rpm. This noise is very regular. Like I say - it is strong and all, and shows no other signs of trouble but continously makes that noise. It is a bit louder when cold. I have 55k on this engine.

My specific questions are: IF YOU KNOW WHAT IT MIGHT BE:
1) Can I just keep on driving it and I should be OK?
2) Should I take immediate action to correct it?

I used to have a 1993 Nissan Altima which made exact same noise when cold at low rpm only - I put on about 15k (with this noise) miles on it and it never showed sign of additional trouble. Please, help!

nevermind... it was the AC pulley