Mystery rattling noise- help me solve it

Hey everyone,
So last month, I went in for an oil change and tire roto. About 5 minutes after leaving the dealership I noticed this weird noise so I brought it back in.
Told them their tech messed something up and they scheduled me for a free diagnostic.

2 diagnostic tests later and they dont know what it could be, wasn’t a loose skid plate rattling and wasnt the anti rattle clips on the brakes

Symptoms:
Rattling/groaning at low speeds like waiting at a red light or while parking.
Hear it most in foward idle or reverse idle especially while depressing the brake, or at very low speed like rolling through s drive thru. Noise seems to go away when in neutral or going normal driving speeds.


Not super easy to hear in the video, sort of comes and goes
https://youtube.com/shorts/Ijlm7yWDCC4?feature=share

Here is one more video. I’m stopped with my foot on the brake shifting between reverse and neutral. You can hear it quiet down and run normally in neutral.
https://youtube.com/shorts/1vdKExfMJF0?feature=share

 

Any chance you can post a video with the sound?

There's some well trained ears on here, haha

 

Surprised they weren’t able to isolate the noise on-site b/c with some audio several ppl on this forum might diagnose in ten minutes…

Hopefully it’s something simple and they’re not covering up a major screw up. Good luck

 

Catalytic converter Heat shield?

 

I'm 100% positive your right. Let's wait and see. I chased a rattle identical to this after installing all my under plates. I even took them all off and put in nylon Washers so I didn't have metal to metal... after 6 months and hours of trying to fix. It was the God damned cat heat shields

 

Sounds like heat shields like said above, light and metallic sounding. Go under and bend them all back.

 

they might have drained your transmission.

 

I realize this was after a trip to the dealer,back in the 70's buddy bought a new Torino and it came with crazy rattle,only some times,finally all most a year later a tech opened up the passenger door to find a empty pop/cola bottle in it

 

Probs the shield or something not bolted in all the way. Sounds like its getting in a standard wave of vibrations that are causing the rattle. Try to tighten all bolts ?

 

Added one more video.
I’ll check the cat heat shield, thanks.

 

It almost sounds like a loose muffler hitting frame or someting solid like a hanger broke loose. Obviously not the loud clicking from shifting

 

Mine started making a similar rattle a few days ago. Got underneath to check things out yesterday. The heat shield over the exhaust on the passenger side dropped and was only hanging on by 1 bolt. The shield slipped though 2 bolts. An oversized washer fixed it.

 

Stop taking vids and get under the stupid truck Nancy

 

Lmao that’s fair
I will when I get a chance. Snowed this morning…
It’s hard to pinpoint! Even the dealer is cant find it…

 

Take a light rubber mallet with you and very lightly tap on exhaust, cat, frame, etc.

 

Look cautiously!

 

well who knows, it happened to me a few times in my engine compartment- coachwhips and a rattler.

I can handle rattlers, but man, those Coachwhips will chase you!

 

Good point. Bring a machete and shotgun too…

Two years ago, I am in my back yard cleaning up our fruit trees. We have a large rockpile, about 10 foot wide by 40 foot long, and 2 foot deep next to my peach tree.
A rattler rattles very loud, maybe 3 foot away from my boots and in the brush where I cannot see him.
Lets just say I left in a jiffy.

Last summer, my 75 year old neighbour is reaching down to grab her coiled up garden hose. A rattler is coiled up inside it, and rattles just as she reaches to grab the hose from the ground. She screams and jumps back. They left the rattler alone and a few hours later he was gone.

Yup, good to be on your toes.

Maybe just ignore the truck rattle and live with it…

 

Keep your head on a swivel, even at night! We were about to pass this fella when I caught it with the edge of the flashlight’s beam…barely.

 

Haha i was just busting balls, if it was a loose cat heat shield I hope a dealership would have spotted it?

Just make sure to WAIT UNTIL THE TRUCK IS COLD before you get under there, especially if you'll be tapping on the cats.

My SR5 4 banger was making a similar sound about 2 weeks ago it was indeed that stupid heat shield. Got 3 super long stainless steel zip ties and wrapped it tight, no more rattling.