I have an 06 Range Rover HSE and I had some loud squeaking about a month ago which sounds like the belts. I had the serpentine belts replaced. The sound went away for about a week and a half. After that it returned! Then I had the tensioner replaced. Sound came back after two weeks! Oddly enough, the sound only occurs when I crank up the truck in the morning when it's cold outside. At times, well, most of the time, after driving it for some time, the sound goes away. The mechanic shop that I went to doesn't seem to quite know what they are talking about, as if they are guessing.... What could be the problem?