Loud humming sound coming from air filter box.

2001 FORD CROWN VICTORIA
158,000 MILES • 4.6L • V8 • RWD • AUTOMATIC
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MASSEY0922
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  • 1 POST
Replaced plugs and boots 1st as part of a tune-up. After about 50 miles, had issue with starting and keeping at idle while in park. Replaced IAC valve, worked for about 25 miles. Then comes in this loud humming sound from air filter box that only starts while NOT accelerating. As soon as I start accelerating, goes away. Take my foot off gas, starts up again. Once it starts humming it'll go for about 20-30 seconds before it subsides on its own then repeats after idle range is hit again.
Nov 5, 2014 at 1:53 AM
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WRENCHTECH
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I have dealt with this noise before. tt is a byproduct of the IAC having a remote tube connected to the intake. What we did to quiet it was t put a piece of foam in the hose to dampen the harmonics. I believe there was a TSB on tis at one time but I can't find it now. There may even be a modified hose available from the dealer.
Nov 5, 2014 at 2:21 AM