ive got an 04 f-150 hertage 4.2 V6 and when driving down the road at arround 35 mph and up i get a roaring noise coming from the engine compartment every time i give it gas and its a lot worse with the windows rolled up. thought it could be the stock intake. any ideas on how to fix this would appreciated.

 

You sure it's not the clutch fan? The stock intake is quiet.

 

im not sure is there anyway to tell.

 

Had the same thing happen on my old GMC, the bearing in the fan clutch locked up so the fan spun at the same RPM as the motor, loud as hell.

With the motor off, take a close look at the fan clutch and the bearing. You should be able to move the fan a bit by hand.

 

i tried moving the fan and it moves easily in both directions and doesnt look to be damaged.

 

i replaced the fan clutch and the noise is still there. what else can I try?

 

Sounds vacuum related. Check to see if your vacuum hose is plugged into your brake booster. Check all your vacuum lines, and make sure your pcv valve didn't pop out of the valve cover. Also check to see that your intake tube is securely fastened to your throttle body and air cleaner assembly.