I have a 2012 Mazda Cx 9 Grand touring, V6 with 122k miles. It runs fine but on start-up after it's been sitting it makes a whining noise right at first. What could it be? I thought it was a loose pulley but when I listened under the hood it almost sounded like it came from the right side of the engine, where the air cleaner is located. it generally makes the sound much louder if it's been sitting for a day or two.I just purchased this vehicle two months ago and I did have my mechanic that I've been using for over 12 years look at it first and he said everything looked great.
The bearing on the idler pulley could be wearing out. The same whining noise occurred on my 2005 Subaru Outback 3.0 Flat Six. Solution is to replace the idler pulley & bearing assembly. Minor repair, not too expensive.
Thanks for the input. I was leaning toward a pulley being the culprit. Easy to check. Thanks
The shop determined which pulley had a problem by removing the serpentine belt and finding out which one had excessive friction. It could be alternator, idler pulley, tensioner pulley, etc.
Another way to find the squeaky is here.
https://www.youtube.com/watch?v=fHtLH_m9gN4
awesome video. thanks guruNorth
