Hi guys, new to this site and am coming here since my dealership is pretty much worthless with troubleshooting a problem I have.

I have '03 F250 super duty with the V10. For about the last 15 months I've had a mystery rattle that occured only during acceleration and only at 25 and 35 mph. The noise is a tinny sound almost like a loose heat shield. I've had it in to the dealership 10 times and they've tightened every heat shield they could find with no luck clearing the rattle. They said I had a crack in the weld of my exhaust so I took it in to my exhaust guy who patched the weld and it didn't fix the noise. Next they said it was my catalytic converter and they replaced it and now the noise is louder, has changed pitch, and occurs more frequently, now including 15 mph along with 25 and 35 mph (still only during acceleration). Now the dealership wants to tear into my transmission saying they now think it's the torque converter. I think they're just guessing at this point. I have no issues with shifting or sluggishness at all when my truck shifts gears, and since the noise occurs more often since they changed out the cat I'm of the belief the rattle may still be associated with my exhaust.

The noise is coming from somewhere near the front of the vehicle, but since I hear it when I'm driving it's difficult to narrow it down. There is no vibration associated with the noise. The rattle is loud enough that when I drive through a neighborhood the noise reverberates off the houses and people actually stop and look at me when they hear the sound.

Do any of you guys have any ideas or guesses as to what may be rattling? Thanks so much!

 

i would check both ur cv joints. can you feel it in your steering at all?

 

No, nothing in my steering.

I also forgot to mention the rattle only occurs after the engine has been warmed up. If it's cold, no rattle.

 

since it is in the front of the exaust, it echos around large passing objects, and you've had other holes in the exaust fixed in the past ide almost put money down that you have an exaust leak before the cat. It sounds similar to a heat shield rattle, but it is louder! An easy way to test/ find out where or if you have a leak is with the truck running and lifted off the ground (unless you want to crawl under it). Have someone take a clip board or something over the tail pipe and while undernieth you will hear a high pitched wistleing noise where the leak is. Also if your just looking at it from under nieth you may see black soot marks where the leak is also but that may not happen since you have resently had parts replaced. Good luck, and let me know what you find.

 

I have a 99 F250 V10 4X4 with the same rattle. What I have found is the Y pipe is hitting the cross member at low RPM. Do not let them get into the trans, my truck has a 5 speed stick shift. Look at the exhaust befor the converter and you will see the pipe is very close to the cross member. I plan to heat the pipe and fold it in a little so it will not touch