grinding noise, with cold engine Options

[skogs]

Hi. When i've started up my engine when its cold it makes a grinding noise thats louder than the engine itself. It could sound like lots of air passing through for example a bad air filter, but i've changed that, and the noise didn't change at all. Could also sound like a bad bearing, but the engine runs perfectly fine, and the sound has been there since i bought the car some 50 000km ago.
The sound quiets down as the engines getting warmer.

Is this a common problem? any ideas what it could be? I cant seem to find any breather hoses connected to the air filter, or any breather filters in the engine bay, could this have anything to do with it?

This post has been edited by skogs: May 16, 2009 - 8:30 AM

[enderswift]

a video showing where the sound is more or less coming from would be a big help. Your description is a vague and your problem could be anything, small or serious

[enderswift]

something occurred to me, do you have a short ram/ cold air intake installed? because once you remove the resonators and air boxes attached to your stock intake, noise levels from rushing air go up considerably. This noise then quiets down as the engine warms up.... since you said that you've had this noise for the last 50k, i highly doubt its a bad bearing, or anything internal for that matter.