What's this noise?


I drive a 2004 F150 Lariat. This past May I had a custom exhaust put in, back rotors replaced, front brake pads replaced, and I put in a cold air intake. I had the exhaust done about a week before the cold air intake was put in, and about two weeks prior to the brake work (different shops). The mechanic that worked on the brakes told me to expect some noise from the brakes for a little bit because they were new pads and they had to break in. So initially I though nothing of the sound that I was hearing when I accelerated. (*note: the noise only started after the brake work)

I drove the truck for about two weeks, no more than 100 miles, and then went away for work the entire summer. I got back mid August and have put on around 200 miles since.

The sound never went away. Basically, there is a Rattling sound coming from the driver-side wheel area that I only hear when I am accelerating. At low speeds like under 10 mph it doesn’t make a sound, and at high speeds if it starts to make the sound and I just let off the gas a little then press back on it the sound will go away until I about two or three seconds after I start to accelerate again.It sounds like something is loose, pretty hard to explain really. I’ve taken it back to the mechanic that worked on the brakes, twice, and he couldn’t find where the noise was coming from, but he’s pretty sure that it has nothing to do with the brakes.


Very unlikely rattling while accelerating is due to brakes.
Where is the CAI inlet? Near the wheel wheel well? They often are noisy.
Those cone filters can let more dirt into the engine, b.t.w.
Make sure the exhaust pipe isn’t close to or touching the chassis.

Had a mysterious noise similar to that, ended up being a broken muffler clamp doing a free rage ride on occasion. too many options, but bad motor or trans mount might be a good starting place.

Try pushing the brake while accelerating and the sound does not go away, then it’s not the brakes. I would start looking at new intake or exhaust. If you have the old intake, you could reinstall it.