[mongoose1951]

Hi,
On my 2004 330Ci with 220,000 miles.
When cold the engine makes a loud whine noise especially when accelerating, goes away when at operating temperature. Also there is a lot of mechanical noise inside the engine, goes away after engine is warm.
Big problem, or little problem?
Thanks

[tjbuggy2b]

Depends on the noise but I'm guessing it's not good, either way.

[CTSean]

Check the secondary air pump which should be easy to tell if the noise at start up and while cold is coming from it.

"Alot of mechanical noise" is not enough to really say anything. try and determine the source of the noise or maybe record a video and someone may be able to identify the noise.