Strange rattling sound from exhaust system

[MSMStannyl]

Hey guys,
I already have plans to take it to the dealership next Tuesday but was curious if anyone might have any idea what this sound could be or if I could be doing any serious damage by continuing to drive the car through the weekend.

This is a 2015 GT Premium (6-speed manual). It is completely stock.

The sound started (at least I noticed it) a few days ago. It's really prevalent for the first few seconds of a cold start as can be heard in the video. It scared the hell out of me at first because it took on the sound of really loud valve tap. However, I then realized it was coming from underneath the middle of the car.

Yesterday, I took the car to my buddies shop to get an oil change. While they had it on the lift, I asked them to take a look to see what it could be. I thought it might've just been a loose heat shield or something along those lines. After inspecting it, I'm being told that it appears to be coming from around the flex connection in the exhaust, just behind the cat (passenger side I think). The mechanic said when he tapped on the pipe, you could hear something rattling inside. I'm wondering if something happened with one of the cats?

Anyway, just figured I'd throw this out there to see if anyone had any ideas. Other than that, I'll know for sure next week when I drop it off at Ford.

<iframe width="420" height="315" src="https://www.youtube.com/embed/9wgES-u_aMg" frameborder="0" allowfullscreen></iframe>

P.S. - I've never embedded video before so hopefully this ^ works.

EDIT - It didn't work. Here's a link to the YT video I took:

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[MSMStannyl]

Well, this is weird. It appears that whatever was causing that sound, has gone away. I'm not getting any kind of rattle anymore. Wondering if whatever it was got blown out of the exhaust somehow. Still has me a bit concerned as to what that could've been. Hopefully it's not a wasted trip to the dealership. At this point all I've got is the video...

 

[Mvalenti]

I had the same thing. I thought it was the sleeve bearing/clutch fork on the tranny shaft. Mine went away as well.

 

[astolt12]

it goes away after you cracked the throttle though, that exhaust on a cold start couldnt get hot enough that fast to close up any gaps or something.

If you get it going again try putting in your clutch asap. if the sound goes away it might be the throwout bearing or something in the driveline.

Interesting none the less...glad it went away!

 

[wilkinda65]

Mine makes the same noise and within 5 to 10 seconds its gone. I initially thought it was a throwout bearing and tried on cold starts putting the clutch in and letting it out in neutral and it makes no difference....

 

[Mako_254]

Mine started off doing this a little bit and it got worse and worse over time. It stopped two days before I took it to the dealer yesterday. Obviously whatever was causing it has failed. I have another rattle at 1500 and 2500 rmps when under load. Dealer says rattle is due to resonator and that there is a TSB for it. Resonator is now on Back order.

 

[TungstenGT]

I took mine in last night for this issue - exhaust rattle at startup. As others have stated, there is a tsb for it. Parts are on backorder. Weird thing is the guy said the new parts are different from the oem parts. Faulty design, I guess.

 

[JRuss]

SSM 45172 - 2015 3.7L And 5.0L Mustang- Exhaust Rattle, Knock Noise
Some 2015 Model Year Mustang vehicle built on or before 3/30/15, equipped with 3.7L Duratec 4V and 5.0L Ti-VCT V8 engines may exhibit exhaust rattle/knock noise emitting from the muffler resonator. Elevating idle to 1500 RPM and performingthrottle tip-in, tip-out events in neutral will assist in confirming noise concern and is not to be confused with an exhaust leak that was addressed with a previously released TSB on 2015 Mustang 5.0L Ti-VCT V8 equipped vehicles. Updated muffler resonator assemblies are now available to resolve vehicle concern. Reference Workshop Manual Section 309-00B or 309-00C Exhaust System for component location and Removal and Installation procedure.

APPLICABLE VEHICLES
2015 CAR: ZG MUSTANG (S550)
2015 CAR: ZG MUSTANG (S550)
2015 CAR: 00071 MUSTANG
2015 CAR: 00071 MUSTANG

 

[TungstenGT]

All fixed now. I swear the new exhaust - they replaced everything from the cats back - is louder and deeper than the oem exhaust. I like it!

 

[JRuss]

Exhaust Rattle

You guys with the exhaust rattle. Did you start hearing the rattle soon after purchase or did it show up later?

 

[GG]

about 6 months in for mine ~6000miles

 

[SC_Sport_Pilot]

Mine showed up after 12000 miles. Took it in and they said the problem is a known
issue with the resonator.

 

[SC_Sport_Pilot]

Got my exhaust system replaced yesterday and the rattle is gone. Both my wife and
I think the car sounds louder now. Wondering if they redesigned the stock 5.0 exhaust
system. Whatever it is my car is now back to it's normal self, exciting to drive.

 

[surfs1st]

Took mine in last week for this. Replaced exhaust from CAT back

 

[andy820305]

It happen to my car this week. i have roush AB exhaust on it. Will the dealer fix this problem for free?

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