OK, I am new to this forum, but I am at my wits end with my 2004 F150 Lariat. It rattles at about 2200rpm, whether I am towing or not. I have gone out and spend the $$$$$ to have the plugs replaced (only one was cracked off) at Fords suggestion but the truck still rattles. Can anyone help me out? Is it possible the catalytic converter is gone as a result of one of my lifters having been replaced last year? I like the truck, but I am getting frustrated at the lack of assistance at Ford unless there are $$$$ involved.

 

Im not sure about your truck but i know on my truck i kept hearing a a rattle. and i found out that it was the heat sheild around the converterl. the weld must have just broke. you could start by just checking that.

 

Thanks Jr_WaxDr,

That is a good place to start I am planning on changing the exhaust to get more torque for towing my boat. I am not a mechanic but thought that might be a possibility. Did yours rattle all the tinme or intermittently? My rattles at about 2200 rpm then goes away above or below that, but it seems to be worse when I am towing our boat.

 

hey guys, i've got the exact same problem and at about the same RPM level. It is always when I'm starting off and usually I can hold the gas at the current RPM and keep the sound going. Sometimes it will do it on the interstate when I get on the gas. I checked under my truck tonight and didn't find any broken brackets on the exhaust. I checked the heat shields and they were all solid however there were two areas that seemed possible for touching, one near the catalytic converter, the other close to the drive shaft. I've bent the shield back out of the way and I'll check it out tomorrow to see how things go. I noticed the one near the catty first and adjusted it and drove around town, bent it back and it seemed to change the sound to make it worse, but didn't notice the other (near the driveshaft) until I got back home. It's late and foggy here so I'm going to just see how she goes tomorrow. I'll keep y'all posted.

 

Are you using the Ford spec oil? If not you may get a rattle from the front of the motor. This can be attributed to the lack of lubrication on the timing chain causing a "rattle", however this is usually at higher RPMs.
If the sound seems to becoming from the back of the motor, behind the dash, then it is most likely the heat shield on one of the front catalytic converters. It will sound like BBs in in a tin can.

 

Got the same deal at ~2000 RPM, cruising at about 70mph. Foot has to be on the throttle and I can hear it. At first I thought it was wind rushing through an opening in the window, but once I rolled the window down, I can clearly hear it. To me, it sounds like an exhaust leak but I curious as to who else has encountered this, and more importantly who has fixed it.