I have a 2000 Jeep Wrangler 4.0L six cylinder automatic.
The last couple of weeks I have had a whistling sound under my hood. It goes away when I accelerate; but at cruise or idle; the whistle is there (also when the vehicle is in park). The sound goes away after about ten minutes of driving. The Jeep runs fine; but the whistle is annoying. From what I can tell; it is coming from the driver’s side.
Hey there James,
Have you done a visual check under the hood with the engine running and the problem taking place? I would look for:
1. a vacuum leak…..a rubber hose or connector that might have come loose or broken off.
2. Is this noise related to the a/c system…turn off the a/c compressor to see if the problem goes away or changes pitch
3. is the fan belt tight – a loose fan belt can jump around and vibrate
4. is the air cleaner and the fresh air inlet hose from the air cleaner intact, rub your hands under the hose to make sure there is not a crack in the plastic/rubber.
Most repair shops will take a test drive with you for free and give their opinion….it might be something simple you can repair yourself?