Hello,

I recently bought a 2003 ranger edge 3.0 auto trans 4x2 supercab 153k miles as of today. This high pitch noise has been constant,
usually when I am 40-60mph with rpm from 3500 and up. Gets louder when I put my foot on the gas, and will go away instantly when I release the pedal. Won’t happen when in N, haven’t found out if it makes it in R yet. Engine won’t let me rev above 3250 RPM when not moving in P or N so I couldn’t tell if it would or not. Happens from 2nd gear up; makes the noise when in 2nd on the shift selector.

What I have done trying to fix this noise
-replaced serpentine belt, tensioner, and idler pulley
-replaced the camshaft synchronizer
-new rear differential fluid and seal, filled to right amount
-tranny fluid has 4K miles in it
-tried the brake cleaner and IAC trick, saw no difference and grabbed my stethoscope and didn’t hear anything around it.


The truck doesn’t idle bad, just makes the noise when accelerating. Heats up well, no problems.

**When I first bought it, I installed a Spectre air filter, assembly is still the factory. Haven’t tried driving without it in yet.**

Please help me solve this before I lose it over this problem. Thanks! Video is the noise

-Tyler

 

And you don't think its wind noise?
Does it change if you open a window a bit?

Yes, I would try removing air filter to see if noise changes

 

Noise doesn’t change when window is either cracked a little bit or down, windshield looks intact as well as the seal on it. The air filter pulled still makes the noise.

 

I’m thinking maybe I didn’t get an amazing check of the IAC and that could be it?

 

There is a vent cap on the IAC Valve, it just pulls off, "snap on fit", take it off and see if noise changes

The vent lets air out from behind the valve and it can make a whistling noise if valve is leaking a bit

 

Is it to the right of the IAC? If so, I pulled it off and the engine lost the vacuum seal and started shaking really bad. Put it back on.

 

Picture of an IAC Valve here: https://www.explorerforum.com/photop...re_low_res.jpg

Black cap in the center is the vent
Removing cap should in no way effect engine operation, its just a vent to prevent air from being trapped behind valve when it opens all the way for startup
But it valve seal leaks it will cause a whistling noise

Can also look like this: https://bob-ayers.smugmug.com/photos...32_sDK3U-L.jpg

You can only use Motorcraft or Hitachi brand IAC Valves, just FYI, other brands will not work on Rangers reliably