Famous Whistle Noise

[jman_07]

So the check engine problem was fixed. Another strange problem occured which i have read alot about its the whistle noise that is heard around 2000-2500rpm no matter what speed you are at i really dont know what it is but its annoying i replaced the IAC valve its not that. Im not sure what it could be any ideas?????

My Explorer is the 4.0SOHC 2001XLT.

 

[762mm]

So the check engine problem was fixed. Another strange problem occured which i have read alot about its the whistle noise that is heard around 2000-2500rpm no matter what speed you are at i really dont know what it is but its annoying i replaced the IAC valve its not that. Im not sure what it could be any ideas?????

My Explorer is the 4.0SOHC 2001XLT.

Idler, drivebelt, rust hole in the exhaust, water pump, power steering pump, or maybe even chain/camshaft tensioner.

I have had a whistling noise too, and (partially) fixed it by adding a water pump lubricant into my coolant ($5) - now it's gone most of the time. That's after I replaced pretty much everything listed above to get rid of the noise. Good luck, if you find your actual issue, please post it.