Whine / humming at start-up until warm
Mentioned this before, but not heard from anyone with anything similar, or possible causes.
When I start my Alfa 147 there is a whine / humming noise. Sounds like a belt is on too tight and needs to settle down kind of noise.
Once the engine is warm, there is a little whine which I believe is normal for an Alfa.
When cold, it is very loud. One Alfa garage have changed the cambelt and tensioners a few months ago, another have changed the auxilliary belt tensioner. Another garage acknowledged the whine, but said everything looks okay with the belts.
Has anyone experienced this, or is this a one-off with my car? I am wondering if is is likely to be a bearing somewhere on either a pulley or the alternator, or could it really only be a belt tensioner not working as it should be? Seems odd that the cambelt etc has recently been changed, assesses as okay, the auxulliary tensioners etc have been changed, yet still have this whine which 90% clears once warm, only really gets noticeable once warm when the engine revved, not noticeable at steady motorway cruise.
Any ideas, anyone?