I have a '99' F-150 4.2L V6 manual 5-speed that I love. The problem is that i have a rattle/clatter coming from the engine after it is warmed up. Some days I hear it plain as day but other day's it is a lot softer. The rattle happens around 2000 rpm's and if i give it a lot of gas the noise goes away. It sounds like is coming from the driver's side of the engine. I have replaced my egr valve, pcv valve, and have taken off my engine hoist brackets (I heard that they could vibrate and smack up against the engine). I have spent most of my free time for the past couple of months looking for this %@##&@ noise. I am about ready to pull my dang hair out. Please help.
Cufan97

P.S.: It doesn't happen at start up or when the truck is in neutral, stopped, or with the e-brake is on

 

It's your driver side cats. they are notorious for rattling. mine do the same thing and my truck is an 03 with 20k miles on it. there's nothing you can do outside of replacing them. Sometimes the rattle goes away though, so I've heard. The rattling is either the heat shields that are wrapped around the cats, or is the honeycomb filter thats broken inside. Lots of vehicles have rattling cats, it's just how it is. If it really really bothers you than toss on some aftermarket high flow cats, otherwise just get used to it.

Tom

 

Damn that sux!!!!!!!! I have spent all of this time looking hoping that it wasn't them. Well thanx

 

ah, it's even worse with an automatic cause it'll sit there and chatter sitting at a stop light with the truck in drive. If I shift to neutral or park, it'll stop because the engine doesn't vibrate enough to make it clatter. Put it in Drive and sit at a MacDonalds drive through and you can hear the clatter echoeing off the wall, gives me a headache!!!

Tom

 

I put two big hose clamps around the outside of the cat hoping to keep the shield in place. It turned out that when you shake the exhaust the pasanger side you can her something rattling inside like a penney. I heard Ford put a metal name tag between the shield and the cover. Do you think that this could have popped loose and is just rattling around in there?

 

That's a myth. Why would ford hide a name tag between a heat sheild and the cat. If you crawl under your truck and tap on the cat, you can hear it rattle. It just sounds like the rattling of thin tin metal to me. The heat shields aren't really welded together. The top and bottom of the shields are just crimped together. I think if the crimps vibrate loose a bit, they will make the rattling noise. I tested this theory out by banging on the cat, then squishing the crimps together more, and banging again. The rattling was reduced after I squished the crimps. If I had a more powerful tool...or more muscles...i'd be able to crimp it better. If you've got access to an arc welder, you can probably solve your problem by welding the upper and lower covers together. crawl under there and check it out real good, you'll see.

Oh yeah, I have a metal tag that says "Ford Motor Company, Made in Mexico" INSIDE my radiator, and i think it broke off and is now clogging my radiator and causing my truck to overheat. Hmm, i don't know why they just couldn't stamp the outside of the radiator with that info, i mean, who's going to see it inside anyway? Well, now I have to take my radiator apart. (gee, i hope they didn't put a Ford Motor Company tag INSIDE my gas tank as well, or in my oil pan...awe man, i think my truck is in serious trouble of a massive internal tag break-off that will eventually kill my truck.

Tom

 

It's not a metal tag, it's your cats. I already fought this battle,and as a result, I now have a hollow shell where my 1st driver's side cat used to be. Search my threads about rattling cats. Just remove the cats, and replace them with Magnaflow high flowcats.

 

I agree.

Tom

 

O.K. thanks for the input. I didn't really believe the whole metal tag thing but I was just relaying something that someone told me. Damn cats!!!!!!!! Always causing annoying problems

 

My t-shirts and tank tops have metal tags. they never fade in the wash.

 

my socks have sharp metal tags on the inside of them and are always cutting my feet up, any suggestions?

 

O.K. i get the point

 

Tom,

try filing down the tags to a smooth edge, rounding out corners. For harder metals, i recommend a rasp or die grinder.

cufan97,
don't take it offensively. we just joke around a lot because....um....well, it's fun. Lots of people here just bash each other day in and day out, espeacially Busa. 2 weeks ago i had 3 posts, now i've got over 250 posts. I had to defend myself like i was running through a gauntlet, all these remarks about my missing teeth and eye patch. But i've learned to forgive them, and get the information necessary to have a happy truck

Have fun!

 

Figures, I always seem to get singled out!!!

I'm not so bad

I'm a very lovable guy, really

And all i want to do is be friends and play nice with everyone else

He he

Maybe i'm just a baaaaaddd boyyyy and need a spanking

Are there any female poster's on here????

Tom

 

that's like a child's picture book!!!!