Rattle near bank 1 sensor 1

[bMelt389]

New to the forum!

I’ve got a stock 05 Ford Explorer XLT 4.0 with about 160k miles. It runs great, drives great, but (as of this week) it sounds awful.

No rough idle and the rattle doesn’t worsen/lessen depending on the RPM. It’s a constant, consistently loud, rattle coming from (what seems like) where my passenger side manifold meets my CAT. It’s right behind my RF wheel, I just can’t figure out where exactly it’s coming from.

I’ve seen a LOT of videos about the timing chain tensioner. And it kinda sounds like it’s near the rear so I’m not saying that’s not it, but it seems too consistent without regard to my RPM for it to be the chain.

Just a little back story, I had a leak in one of my coolant lines that was slowly pouring coolant out onto my exhaust, right where the sound seem to be coming from. Could this have warped my CAT? Could there be something broken off inside my CAT? My O2 sensors are reading fine with the exception of some inconsistent low voltage on sensor 2.

Has anyone heard of this? I work a full time and 2 pastime jobs and I’m raising two kids so I just don’t have the time to go in and start pulling things out. Really hoping this sounds familiar to someone in here.

Anybody?

 

[Rick]

Check the exhaust heat shields. They often come loose and rattle.

 

[bMelt389]

Check the exhaust heat shields. They often come loose and rattle.

heat shield was my first thought. I figured it may have warped with the coolant hitting it after it got hot from driving. But that’s not it. It sounds like the “rock in can” sound but it’s a much louder rattle than that. I’m noticing zero performance issues and I’ve hooked a scanner to it and no codes. I’m just lost at this point and really don’t wanna have to pull my exhaust apart if I’m barking up the wrong tree

 

[CallMeSyd]

heat shield was my first thought. I figured it may have warped with the coolant hitting it after it got hot from driving. But that’s not it. It sounds like the “rock in can” sound but it’s a much louder rattle than that. I’m noticing zero performance issues and I’ve hooked a scanner to it and no codes. I’m just lost at this point and really don’t wanna have to pull my exhaust apart if I’m barking up the wrong tree

That's the only thing I can think of as well. Heat shield could be contacting the exhaust. Also, the heat shield that is actually attached to the cat may have detached at some point. Anything else I can think of would change with RPM.