Rattle/Chirp Sound coming from rear

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
Hey guys,

I installed my LethaPerformance off road xpipe a couple a weeks ago and i'm experiencing a loud rattle/chirp sound coming from the the rear of the car. I'm almost certain that it's coming from the trunk. I searched throughout the trunk, took the seats out, tire/jack, trunk liner...) I checked for loose bolts as well. I checked underneath the car cant find anything touching or loose.

The sound generates if I get on it and then after that, any small bump will make that sound or any acceleration. I noticed if I don't drive hard, or go into higher RPMS (around 3k) I don't hear the sound at all. No sound comes from when I start the car or Idle.

Hoping someone has experience this and fixed it.

Thanks,
Jon
 

Sonic 03 Cobra

Yes, that's a 2011
Established Member
Joined
Jun 16, 2002
Messages
1,066
Location
Philadelphia, PA
Sounds like a sound I used to have. Check the clearance between the muffler hangers and the muffler. Mine were making metal on metal contact, and it got worse when everything was warmed up. I took some fuel line from the parts store and put that around the hanger on the muffler. Problem solved. The correct fix to this is to shorten the length of the over axle tube by .25-.5". In my case this was due to my mid pipe on my long tubes being too long.

If it's more of a banging sound then check the rotation of the over axle tube. It's probably not clocked correctly and making contact with the spare wheel well.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
Ok I'll check it out. Did you have after market axle backs? I've had roush axle backs for a while and never made a noise until I got the xpipe. I do remember now that another person with the lethal performance xpipe made his muffler tips stick out a little more.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
I checked and didn't see anything. It sounds like metal to metal contact and it also makes a loud rattle sound like something is loose. I tried looking into the trunk some more and still cant find anything. I might just be unlucky with this one lol.
 

WhiTriCobra

PDP
Established Member
Joined
Oct 7, 2008
Messages
2,362
Location
GA
I would go underneath and shake the midpipe and axle back around. You might be able to duplicate it.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
I would go underneath and shake the midpipe and axle back around. You might be able to duplicate it.

Yeah man, I've been underneath a couple times to check it out. I tried shaking the mid pipe and axlebacks, hit them with my fist, checked for hardware tightness and I did the same for the trunk. I swear it's coming from the trunk it seems like. It's really loud from inside the vehicle.

The weird thing is that after I've driven the car for about 5 min, the noise occurs which would make sense that It's the exhaust parts expanding due to the metals heating up and making the noise but man I swear it's coming from the trunk, the noise is so prominent from the trunk area.

I havn't tried shaking the exhaust around right after I got home so I'll try that while the exhaust parts are still hot if "heat" is the factor. That's the only thing I can think of. Other than that I, I guess I'm SOL.
 

MG0h3

Well-Known Member
Established Member
Joined
Jul 23, 2014
Messages
13,683
Location
El Paso, TX
I saw a thread about a bad pinch weld over the wheel well or behind the rear seat. Guess it would cause some odd noises. I think you need to pull the trunk liner out to see it. On my phone so searching is tough.


Sent from my iPhone using the svtperformance.com mobile app
 

WhiTriCobra

PDP
Established Member
Joined
Oct 7, 2008
Messages
2,362
Location
GA
Maybe have someone riding in the back of your car as you drive it. If you can take it somewhere safe, take the back seat out and have them ride back there as your driving it slow.
 

Sonic 03 Cobra

Yes, that's a 2011
Established Member
Joined
Jun 16, 2002
Messages
1,066
Location
Philadelphia, PA
Sounds exactly like the over axle pipe hitting the spare tire well or the muffler hanger rubbing. Like I said before what you are describing sounds exactly like what I experienced. Took me quite a while to track it down. With the car cool and the suspension loaded, check the clearance between the over axle pipe and the sheet metal. If you don't have at least half inch all around, it is likely your cause. Just loosen the clamps and rotate the pipe to adjust.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
Sounds exactly like the over axle pipe hitting the spare tire well or the muffler hanger rubbing. Like I said before what you are describing sounds exactly like what I experienced. Took me quite a while to track it down. With the car cool and the suspension loaded, check the clearance between the over axle pipe and the sheet metal. If you don't have at least half inch all around, it is likely your cause. Just loosen the clamps and rotate the pipe to adjust.[/QUOTE

ok i'll check again, maybe i missed something the first time around.I will check it after work. Thanks
 

gt5.0coyote

Well-Known Member
Established Member
Joined
Dec 7, 2014
Messages
1,369
Location
Williston fl
I have Roush Axle Backs and a LethalPerformance 3" O/R Xpipe. The muffler still seems good.


Hmm only other thing really is that your OTA pipe could be rubbing where the spare sits. One of our Pypes o/r x pipes also vibrated hen we first put it on. It was defiantly coming from the x pipe. We also had the cammed tune on and it really vibrated at idle. It eventually went away though.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
Hmm only other thing really is that your OTA pipe could be rubbing where the spare sits. One of our Pypes o/r x pipes also vibrated hen we first put it on. It was defiantly coming from the x pipe. We also had the cammed tune on and it really vibrated at idle. It eventually went away though.

it's weird, yesterday there were some light rain and the noise was just about non existent lol But like you said and another one said, ill check the clearance.
 

gt5.0coyote

Well-Known Member
Established Member
Joined
Dec 7, 2014
Messages
1,369
Location
Williston fl
it's weird, yesterday there were some light rain and the noise was just about non existent lol But like you said and another one said, ill check the clearance.

Wow that really weird lol. Our vibration in the x was coming from the flex portion that pypes puts in. Let us know if that works brother!
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
I checked underneath once again and there is no rubbing on the exhaust parts. Clearance is good. I stripped everything from the back seats and back. I am really baffled that I can't find the noise lol.... I think I will just call it quits and deal with it lol. Maybe I'll find it by accident later down the road.
 

coffeebowl

Member
Established Member
Joined
Jul 10, 2016
Messages
31
Location
Tennessee
Update on the noise.

Immediately after driving, I looked underneath my car and noticed that one of my hangers was close to the bracket that holds the hanger. That's due to the metals expanding from the heat i'm guessing. When I checked underneath the car looking for the noise, it was always cold and the clearance was great.

The solution was that I just took a file to the bracket just enough to where the hanger doesn't touch. I didn't have to file much at all and the noise is completely gone.
 
Last edited:

Users who are viewing this thread



Top