Unknown Rattle noise under car - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Wallis1986 · 09-25-2017, 03:09 AM

Hi Everyone,
Just seeing if anyone might have an idea of a noise im hearing under the car. If I take the car out for a regular cruise its dosnt do it, but seems to start if i give it a bit of a flogging. from then on for the rest of that cruise it seems to make a bit of a noise under the car that sounds like a bit of a mix of a semi flat tyre at times or sound a bit like a rattley clunky noise. some times it feels a bit like loose wheel nuts but its definately not. i can sort of feel it in the floor and handbrake while its doing it. It even stil does it when im just parked idling but only a bit. mainly does it on deceleration. Once its been parked up for a while it goes back to normal untill i up it again.
I jacked it up today to see if i can find it. Wheel bearings seem ok and wheels spin with no noises from brakes or anything, what i have notice is the driveshaft has some play in it. It seems to have about 10 degrees free play before it clunks each way. Could that be the noise im hearing?
The car is a SS with an LSA and Upraded 6 Speed manual transplant and a few engine mods. 620rwhp . So im assuming the rest of the drive line is due to fail at some stage.
Its doing my head in not knowing what the sound is, any ideas would be greatly appreciated.
Thanks

Skyblu · 09-27-2017, 01:36 PM

it may be the baffles in your mufflers, you didn't say what year your car is but mine is 2010 and had a rattling noise I couldn't figure out either right away but it was a loose baffle in the muffler, threw them out and ordered some cat back borlas. The replacement gm huge muffler was more than the borlas!

Wallis1986 · 09-28-2017, 02:51 AM

Thanks for the reply, sorry its a 2010 but its an aftermarket exhaust. The sound only starts after giving it a bit of a flogging. and goes away after i park up for a bit. Really wierd and hard to describe. I can feel it in the handbrake lever and a bit through the floor.

rwhxk3 · 09-30-2017, 03:07 AM

Could it be the tunnel brace banging against the exhaust? What diameter is your exhaust?

Sent from my iPhone using Tapatalk Pro

chuckie669 · 09-30-2017, 07:14 AM

I had a strange gremlin for a while but it was a more metallic sound. Looked and looked and found nothing. Finally one day under my car I noticed a small metal line plugged into a rubber overflow tube south of the transmission on passenger side.

The bolt had backed out and since then would occasionally shift to resonating off the exhaust until it would shift back off and be quiet again.

09-25-2017, 03:09 AM	#1
Wallis1986 Drives: Black beast Join Date: Sep 2017 Location: Bowen Posts: 24	Unknown Rattle noise under car Hi Everyone, Just seeing if anyone might have an idea of a noise im hearing under the car. If I take the car out for a regular cruise its dosnt do it, but seems to start if i give it a bit of a flogging. from then on for the rest of that cruise it seems to make a bit of a noise under the car that sounds like a bit of a mix of a semi flat tyre at times or sound a bit like a rattley clunky noise. some times it feels a bit like loose wheel nuts but its definately not. i can sort of feel it in the floor and handbrake while its doing it. It even stil does it when im just parked idling but only a bit. mainly does it on deceleration. Once its been parked up for a while it goes back to normal untill i up it again. I jacked it up today to see if i can find it. Wheel bearings seem ok and wheels spin with no noises from brakes or anything, what i have notice is the driveshaft has some play in it. It seems to have about 10 degrees free play before it clunks each way. Could that be the noise im hearing? The car is a SS with an LSA and Upraded 6 Speed manual transplant and a few engine mods. 620rwhp . So im assuming the rest of the drive line is due to fail at some stage. Its doing my head in not knowing what the sound is, any ideas would be greatly appreciated. Thanks

09-27-2017, 01:36 PM	#2
Skyblu Drives: 2010 Aqua blue 2SS/RS M6 Join Date: Jul 2009 Location: Florida Posts: 993	it may be the baffles in your mufflers, you didn't say what year your car is but mine is 2010 and had a rattling noise I couldn't figure out either right away but it was a loose baffle in the muffler, threw them out and ordered some cat back borlas. The replacement gm huge muffler was more than the borlas!

09-28-2017, 02:51 AM	#3
Wallis1986 Drives: Black beast Join Date: Sep 2017 Location: Bowen Posts: 24	Thanks for the reply, sorry its a 2010 but its an aftermarket exhaust. The sound only starts after giving it a bit of a flogging. and goes away after i park up for a bit. Really wierd and hard to describe. I can feel it in the handbrake lever and a bit through the floor.

09-30-2017, 03:07 AM	#4
rwhxk3 S1N1STR Drives: 2013 Camaro 2SS Join Date: Aug 2013 Location: Oklahoma City, OK Posts: 1,091 View My Garage	Could it be the tunnel brace banging against the exhaust? What diameter is your exhaust? Sent from my iPhone using Tapatalk Pro

09-30-2017, 07:14 AM	#5
chuckie669 Drives: 2011 ss Join Date: Sep 2015 Location: E-TX Posts: 764	I had a strange gremlin for a while but it was a more metallic sound. Looked and looked and found nothing. Finally one day under my car I noticed a small metal line plugged into a rubber overflow tube south of the transmission on passenger side. The bolt had backed out and since then would occasionally shift to resonating off the exhaust until it would shift back off and be quiet again.