Rattling under 4Runner

[treekanay]

I have a crazy metal on metal rattling sound coming from under my 2005 4Runner. It has an aftermarket Borla catback exhaust. I thought it was a heat shield but when I crawled underneath, they were bolted down tight. It sounded like it's coming from the muffler. It goes away when you hold one of the tailpipes to keep it from vibrating. Any clues?

 

[having fun]

If it goes away by holding/stopping the vibration from the tail pipe. Sound like you have narrowed down the component.

Fire it up and crawl the underside, find the noise.

 

[riceandpho]

check all exhaust hanger, if its broken, usually borla will send replacement. check all pipes for rubbing.

 

[treekanay]

Sorry, I was too vague. I did crawl underneath while it was running. The hangers seemed pretty solid. I couldn't find any metal to metal contact. It was coming from inside the muffler as far as I could tell. What could be rattling like that inside of the muffler?

 

[AuSeeker]

If I'm not mistaken doesn't Borla have a good warranty?

If so and you're the orignal purchaser of the Borla system take it in and let them find the issue.

https://www.borla.com/support/million-mile-warranty/

 

[Inv4drZm]

Sorry, I was too vague. I did crawl underneath while it was running. The hangers seemed pretty solid. I couldn't find any metal to metal contact. It was coming from inside the muffler as far as I could tell. What could be rattling like that inside of the muffler?

My brother bought the Doug Thorley Y pipe for his FJ. After a month or two it started a high-pitch rattle like a metal bb rattling around metal on metal. He took of the Y pipe and shook it up and down, yep, the noise was from the cat on the pipe. Warrantied it and got sent a new one. However the new one has been making the same exact noise after a couple weeks.

There could be something similar going on with your muffler. Maybe pull it and shake it by hand?

 

[South-O 4RnR]

I had/have this issue. In the right condition, the exhaust will rattle against the rear axle. I've cut off the hangers and reapplied after pulling the pipe closer to the body of the truck. I think the rubber hangers stretch out over time and mine need to be replaced.

 

[Bob J]

I had an annoying rattle that turned out to be a metal sheet over the muffler that had come loose... I think it was there to isolate the heat of the muffler from the body.. If the sound is "tinny" you might see if that is your problem....

 

[Billynath1988]

I have also been chasing an annoying rattle that took me almost a year to figure out.

Spring bolt joint on the exhaust..
http://www.toyota-4runner.org/4th-g...ng-clanking-jingling-noise-finally-found.html

also check, panhard bar, rear shock bushings, heat shields.... ect