4.0L SOHC High Pitched Whistling Noise

[CDW6212R]

Not a whistle, exactly. More like a very high-pitched humming noise. Sometimes intermittent, sometimes constant. But most importantly, it occurs only when all three conditions above are present (ie, hot day, high speed, & vehicle has been running for at least 10 minutes).

Try the DPFE sensor again, remove the cover atop the engine, and listen closely right there at the top. My 302 engine does that occasionally, just a slight moaning at idle when warm.

 

[koda2000]

Still sounds electric in nature

My '01 job 2 SOHC makes a very high pitched electrical whistle. I only notice it when the engine is at full operating temp and I get out of the truck to close my gate. If the frequency was any higher only my dogs could hear it. I have no idea what it is. It's not annoying enough for me to spend much time hunting it down and it has no effect on how the engine runs.

 

[delexploder]

fuel pump

 

[koda2000]

fuel pump

No, not if my case. My FP is fairly new and the noise definitely originates from the engine compartment. Thing is, when you open the hood the noise from the clutch fan pretty much drowns out the noise, making it rather impossible to locate. I'm wondering if @donalds may have something in thinking it may have to do with the coil pack... ?

 

[fastpakr]

Just to confirm, it's definitely different from this noise?

 

[Mr. Alligator]

drowns

Just a thought... any difference whether the air conditioner is on or off?

 

[koda2000]

Just a thought... any difference whether the air conditioner is on or off?

Not in my case.