This question is really hard to explain but I well try my hardest. I did not know what topic to put this on so I put it in engines because I think I will get the most answers. I have this weird buzzing noise comming from my truck. It happens the loudest when in drive or rev. with the brakes on but also happens when in park but just not as loud. The sound first sounded like it was a loose fan hitting some plastic or something but it seems more complex than that. If I am in park and bearly tap on the gas it gets really loud but if I keep reving the engine it stops after 200-300rpms. I got under the truck and tried to track down the sound but I leading to like something in the exaust or something it rubbing on my flywheel. I wish I had some audio so yall could listen to it but i have nothing to record it with. The sound is really bugging the heck out of me because when I stop at a red light its so loud people look at me the a state of confusion. I don't want them to think ford sucks so and an trying to fix this ASAP.

 

need toknow what vehicle you have,what motor.etc..

 

lol , I think I know what your talking about cause mine did the same thing. It reallys sucks going through the drivethru at Micky D's with that sound and I had to brake and rev to make it go away. Actually it's more common than you think. Fords released a TSB on this this a while ago.. It's your cat's, usually the drivers side heat shield. Let it cool ,get two band clamps to wrap around your cats and tighten no more than 60 in. lbs. (the two longer one's under the cab, not the forward shorts) from a visual it doesn't look like the heat shields were spot welded as they should be - there flanged for a tight fit. The band clamps worked for me so far, stopped that irritating vibrating screeching sound..Also check out the heat shields that are bolted to your underbody , these can losen as well.

I have the bullitin(ALLDATA.com) in front of me here on another comp that shows illustrations of the procedure - won't let me copy!! Well it finally did but made it a "gif" - o brother, computers and me don't mix..Hope the info above helps anyway..

 

that is the sound jbrew. I dont have my truck right now but when I see it next time I will look and do what u said. thanks.

 

I found the TBS but what are they for. Does the dealer fix it for free because there is info on how to fix any of the problems.

 

Only if you are still under factory warranty. Details are published in the TSB.

Steve

 

well i looked under the truck and the sound is comming from the cat on the driver side and jbrew i think u are on the right track of what the sound is. As I was looking under the truck I saw heat shields the cover the cat and then some closer to the engine. So the question is which shield is it? Mabey pictures would help if you have access to a dig. camara.

 

Sure, infact I was just closing up shop here - I'll take a quick pic -

https://www.f150online.com/galleries...139&anum=10943 - actual Pic

https://www.f150online.com/galleries...140&anum=10943 - drawing from the TSB

 

WOW Great pics. ThanksThanksThanksThanksThanksThanksThanksThanksTh anksThanksThanksThanksThanksThanksThanksThanksThan ksThanksThanksThanksThanksThanksThanksThanksThanks ThanksThanksThanksThanksThanksThanksThanksThanksTh anksThanksThanksThanksThanksThanksThanksThanksThan ksThanksThanksThanksThanksThanksThanksThanksThanks ThanksThanksThanksThanksThanksThanks!!! I will get those clamps on ASAP!!!Ur a life saver!

 

Glad I could help

 

I had the same sound, so I tried this. While I was crawling around trying to find the source of the sound I found out my tail pipe had come loose. The clamp was tight as could be, but the pipe just slipped out of it. I couldn't move the nuts one way or the other. Guess I'll just take it to a muffler shop.