Need your help on this one

[tireman]

01V6 all stock 144k miles. Started to get a low resonant hum in the air intake tube. If I open the air filter box just a bit, you can really hear it! The plastic tubes to the throttle body vibrate to the hum. WTF? Comes and goes, but seems to be getting more persistent. All connections and hoses seem secure. No idle issues, runs great, Just a big hum noise. Anyone??????

 

[joegr]

Is this only at idle?
I've seen (well heard) the IAC (when it is about to fail) do this in other Ford cars, but it would the first that I know of on an LS.

 

[tireman]

hi Joe

no this is odd, the noise is there at idle, then i rev the engine by hand, the noise goes away then comes back even louder as i release the throttle. Seems to be coming from the MAF sensor area. Almost flute sounding. Took off the plastics and checked for cracks then reinstalled, sprayed with foamy water, nothing all seems secure.

 

[G-RELL]

has it been supercharged?!?!?

JK.. you could try the starting fluid leak test (carefully) still sounds leak related.. a video might help

 

[tireman]

no supercharge all stock

144k miles all stock parts, I'll go try the starter fluid and clean the IAC, be back in a few minutes

 

[tireman]

Ok

Sprayed starter fluid all around the pipes, no response. Next took off IAC, about 6 years old, 2nd one. Cleaned it out real good, reinstalled. Started car, noise still there at Idle, but after 30 seconds or so, the noise stops! No noise now, all back to normal. I'll be back later to give an update. Thanks for the tips!

 

[tireman]

IAC seems to be the culprit

60 miles on two trips and the howling of the air intake plastic pipe has stopped. Sounds like a low resonant hum, like a wind pipe, you can feel the vibrations in the plastic pipes from throttle body to air filter. It does get loud! Cleaning out the IAC valve on the throttle body seems to have fixed the problem. Nice and quiet again! Until next time!

 

[tireman]

That must have been it. IAC valve

Seen cleaning there have been no further incidents of the howling noise thru the air induction pipes to the throttle body. Easy fix, just clean the IAC valve.