High-pitch Wistle

[sslogen]

I bought 1998 GS400 six months ago. It was 104K and now it is 111K. I am the third owner. I only replaced new tires, spark plugs and cabin air filter so far and it's been awesome driving. A few days ago I started to hear random high-pitch whistle sound while driving. I rolled down the window to hear if it comes from wheels but it did not. I do not hear the whistle when the engine is running with parked. I never heard such sound before since it is not normal problem related car sounds like knocking, squeaking or rattling. While driving I hear the whistle at 30 mph or 65 mph or any other speed and it lasts 5 seconds to 30 seconds. My GS400 still drives well. Does anyone have good idea on this? I am super sensitive about noise and I don’t want to whistle back when I hear it from my car. :whistles:

[intakerGS]

I experienced a likewise noise at same speeds. Best described as wind blowing through a hole, pardon me language :P

You might have a look under your car and see if the rubber chassis plugs are still in place, also for leaks (a hole) in the exhaust system. In my case, a hole in the muffler explained the concert.

[RoboRam12]

Check for loose vacuum hoses as well. I had a whistling noise that would show up when I got off the gas after accelerating which was due to a vacuum hose.