Cold weather strange engine noise

[joecap]

You can tell the cold weather has arrived with all the new noises. Mine is a very loud engine or air intake noise sounds like air whistling through a small passage. Only occured when it was about 15F a couple of days ago and under throttle. When accelerator was released, sound was gone.

It went away after about 5 minutes of driving. Any ideas?

 

[Sleb]

so many explorers have that & I have not read an answer yet

 

[Joe Dirt]

Sounds like Snowball- was it at idle too, or only under accel? I had tips to the IAC needing to be cleaned, (mine I think needs a gasket, but hasn't duplicated the noise yet, not cold enough)

http://www.explorerforum.com/forums/showthread.php?t=200774

 

[jwright4]

i noticed this same noise on mine now that it's colder here in the north east. I only hear it for a quick second when i first start to drive after a cold start. yesterday i noticed the clamp was lose that held on the intake on the upper side..haven't tested it since i tightened it down.

 

[Donner]

Fuel injectors

I'm just guessing here, but wouldn't that sound be caused by the fuel injectors? The engine is designed to warm up in 15-30 seconds no matter how cold? So the whistling sound would be the increased fuel traveling through the injectors or through the system based on the drop in temps? Close?

 

[E.B. Cornburner]

It's just air whooshing past the throttle plate and/or IAC pintle valve. In the winter, more air and fuel is needed to start and maintain a given RPM till the engine warms up, so you're just hearing more air rushing past.
On my '04, at a certain throttle angle, it makes a "swoosh" or squealing noise. Nothing to get alarmed about, and perfectly normal.

 

[joecap]

Thanks for the input. At this dB level I can't imagine it's normal, I've never heard it on any other vehicle in the cold. Since this is my first winter with the vehicle, I don't know if it was there by design or not.

If I get a chance on a really cold day I will try to isolate it by listening under the hood for the sound. It would be very difficult to duplicate at the service shop since it only occurs on cold start below about 15 F.

 

[CheesePuff]

Yea -- I have an 03 Eddie Bauer 4WD and it's VERY loud this year. Last year I only had the issue when it was below 30 degrees F, and the same this year but it's much louder. It's the loudest when it's at the top of a gear change.

 

[E.B. Cornburner]

You wanna hear a loud one? Check out a GM 3800 V6 supercharged engine on a cold startup. They're even worse with aftermarket intakes on them. It almost sounds like it's got a serious problem, but as the engine warms up, it goes away. Our engines are very quiet compared to them.