Whistle at idle

[jaydez]

I recently noticed that my engine make a whistling sound at idle. It's pretty loud and a few people have commented about it. Is there any common cause I should look for? Or is this completely normal? It's a 4.0L SOHC with a gutted airbox and paper filter BTW.

Nothing seems out of place or disconnected and there are no codes. It runs fine other than that.

 

[Exproblems]

It's a 4.0L SOHC with a gutted airbox and paper filter BTW.>>>>>>>>>>>>>>>>>>>>>>>>>>

I'm thinking you answered your own question here by mentioning your, "gutted air box". My guess is, this is the source of your whistling problem at your air intake. BTW, what exactly do you mean by "gutted air box'? What have you removed from the stock one? I read in here not long ago where some guys modified their air boxes by cutting extra holes in them for better air intake, but this caused a louder, similar whistling sound you are mentioning here.

 

[swshawaii]

Agree with Exproblems, removing the "silencer" will only increase intake sounds.
Also, clean the IAC valve, it will improve the idle, and subdue unwanted noises.

http://www.mysporttrac.com/mysporttrac/projects/CleaningIAC/CLEANING_IAC_MOTOR.htm

 

[Triton8273]

I have done the airbox mod and the whistle is not really noticeable at all. He says people have questioned him about it which makes me think it is something different. I really don't notice any whistling from the airbox at idle.

 

[Exproblems]

I have done the airbox mod and the whistle is not really noticeable at all. He says people have questioned him about it which makes me think it is something different. I really don't notice any whistling from the airbox at idle.

Triton,

did the air box mod help or make any difference in how your Explorer runs now? I would consider doing it on mine, if it will help me get better gas mileage out of this thing. Do you have a "how-to" link on this air box mod? Thanks.