My '02 4.2 has got a slight clanking noise that's getting to be more and more noticeable in lower front somewhere. At first I thought maybe the wheel/rotors but a guy I know says his truck makes the same noise and he had mentioned that it was something coming loose in the cat heat shield. Does this sound familiar to anyone? Truck is stock. Thanks for any help.

 

If it’s the cat heat shield, you can probably fix that yourself, right on the ground. Take a look when it’s cooled off; a loose shield will be obvious. Are you still under warranty?

 

Yes, still under warranty for another 10k or so. I did crawl up underneath and couldn't find anything wrong......then again I have no idea what I'm looking for.

 

It sounds familiar. The cats have thin metal shields over them. Crawl under the truck when it's cold and pry and tap around on all of them. When they're loose, they rattle.

 

MY BROTHER IN LAW HAS A 4.2L AND HIS TRUCK BEGAN TO RUN BAD AND MAKE RATTLES UNDER HIS TRUCK, COME TO FIND OUT THAT HIS CAT HAD BROKEN UP AND BLOCKED OFF HIS EXHAUST

 

What year was his truck, and how many miles did it had? Did he find out what caused it?

 

Cats do rot out, break inside, and cause a rattle. It’s probably from crappy gas over time. Since you’re still under warranty, you should take your truck to the dealership because a bad cat will be covered.

 

HIS TRUCK WAS A 03 HIS CATALYTIC CONVERTER WOULD GET CHERRY RED @ NIGHT IF YOU LOOKED UNDER HIS TRUCK HE THOUGHT IT MIGHT HAVE BEEN CAT SHIELD ALSO BUT IT TURNS OUT THE CAT HAD BROKEN UP WITH 23,000 MILES