Ever since I installed my 80MM throttle bodie I have a constant air noise. This is caused by the throttle bodie being to big for the stock intake manifold. When It's -20 to 20* I have two air whistle's going on. The second air whistle is the fact of cold air going through the plastic intake manifold and causing a whistle through my air intake. It's quit annoying!

 

Air leaking in around air filter. Put in some weater strip seal to make better fit and noise is gone.

 

Wow. Search got me here.

I have a 2006 Expedition that whistles at light throttle I think just when it's cold.

Guess it's the Alternator. Has anyone had any luck getting the dealer to fix this for free when it's out of warranty?

 

I live in Nova Scotia and up until last week it has been warm. Last week it got cooler and on my way to and from work(25 minute drive at highway speeds of 110 kph) I would get the intermittent whistle- first thought it was radio interference. I own an 05 supercrew, 5.4 4x4. Will wait and see if it goes away with warmer weather before replacing alternator. Noise does sound like air slipping through a tight seal but can't find anything yet

 

I complained about my whistle while the truck was still under warranty. They couldn't find or identify the issue. Then, after the truck was out of warranty, I replaced the alternator on my own - fixing the problem. I went back to the dealer and asked to be reimbursed for the new alternator since I had the classic "pre-existing condition." Nope, not gonna happen. I was told.

This and many other similar issues (with both my 2005 and 2010) led to me change brands. Sad but true.