I first noticed this whistling sound during the start of my car one very cold morning. As the car was warming up it would make an intermittent whistle and would also whistle at various RPMs. It would also make the noise while I was driving until the engine was fully warmed up and then it seemed to go away. I decided to record it one morning so I could at least have something to show the techs at the dealership because I knew they wouldn't be able to reproduce it when I showed up with the car warmed up.
I showed the video to a tech at the dealership, he said he's never heard/seen anything like that before. I had done some prior research on the subject as I had this whistling for a couple weeks as the weather progressively got colder. I was making an educated guess as to what the cause could be after reading about various people having issues with the intercooler to throttle body hose coming loose. I also showed them a subaru tech tip from february 2012 (I think it was called "excessive engine noise under boost") which pointed to this issue of hoses frequently coming loose from IC to TB. I asked that they just look at that and anything in the area and tighten things down.
After waiting a couple hours, a service desk guy brought my keys back to me and said they can hear the whistling but can't pinpoint where its coming from and said they tightened down what they could. He also said to just keep any eye on the issue and if the whistling gets louder or any worse to just bring it back to them. I said okay and went on my way.
Prior to having this issues getting looked at I did notice the car didn't seem to "pull as hard" and seemed to "hesitate" when I would try to step on it or do small WOT bursts. After getting my car serviced it seemed like I no longer had this issue on the drive home and the car seemed to pull smoother and harder. Honestly, it could all have been a placebo effect and they didn't tighten anything of importance really, but it did seem to be running smoother. Its only been 2 days since and on cold starts in the morning I don't really hear the whistle sound as much though its still there, just doesn't seem as prominent?
I've seen people suggest taking off the intercooler and reseating all the hoses and putting t-bolt clamps in place of whatever was there before and said this has fixed the issue for them. The problem is I'm not too mechanically-savvy and wouldn't be too sure of what I'm doing if I were to do this by myself, and I'm not sure how far I would get with the dealership seeing as how they couldn't figure out where the noise was coming from in the first place. Anyone have any suggestions as to how I would go about doing this myself so I could ensure all hoses are secure and in place?