Subject:Rattle Noise Under Vehicle - May Be Engine RPM Related

[venice17517]

#PI0027: Rattle Noise Under Vehicle - May Be Engine RPM Related - (Feb 3, 2010)

Subject:Rattle Noise Under Vehicle - May Be Engine RPM Related

Models:2010 Chevrolet Camaro SS
Equipped with 6.2L V8 Engine
Please Refer to GMVIS

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2393338&from=sm#ss1-2393338">Condition/Concern

Some customers may comment on a rattle noise from under the vehicle. This noise is mostly reported when the vehicle is cold and may go away completely when the engine is warm.
It is possible that the internal baffles may be loose in the mufflers on vehicles produced before September 15, 2009 or the resonators on vehicles built before December 1, 2009.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2393338&from=sm#ss2-2393338">Recommendations/Instructions

To diagnose loose baffles in either component, use the following method.

1. <LI type=1>Lift and suitably support the vehicle. <LI type=1>Locate the muffler at the rear of the vehicle. <A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2393338&from=sm#oth3-2393338">Muffler Rattle Diagnosis Tap Points
   
   
   
   
   <LI type=1>Using a rubber mallet, strike the exhaust pipes in the bend just ahead of the mufflers as shown. If loose baffles are present, you should hear them rattle when tapping with the rubber mallet. Replace the exhaust system to correct this condition. Important: You must only tap on the exhaust pipe at the positions shown. Tapping further away from the mufflers may cause other reverberations that do not indicate a need to replace components.
   <LI type=1>Locate the resonator at the mid-point of the vehicle. <A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2393338&from=sm#oth4-2393338">Resonator Rattle Diagnosis Rear Tap Points
   
   
   
   
   <A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2393338&from=sm#oth5-2393338">Resonator Rattle Diagnosis Front Tap Points
   
   
   
   
   <LI type=1>Using a rubber mallet, strike the exhaust pipes both in front of the resonator and behind the resonator as shown. Important: You must only tap on the exhaust pipe at the positions shown. Tapping further away from the resonator may cause other reverberations that do not indicate a need to replace components.
2. If loose baffles are present, you should hear them rattle when tapping with the rubber mallet. Replace the exhaust system to correct this condition.

[don0fthedead]

Thanks for the post!

Looks like I'll be getting this...
"Replace the exhaust system to correct this condition."

[2010 SSRS]

Does GM or the dealership have to fix this, is this like a recall?

[don0fthedead]

I brought my car in the dealership the other day for a noise and I was told that the muffler I have is no longer used. They had to order the parts for it, but they said once it comes in, they'll replace it for me. I was told it shouldn't cost me anything, but once I go in to get it replaced, I'll see for sure.

[gtc352]

I've been looking for that rattle for months. I've torn the whole trunk down, checked every heat shield and lost alot of sleep. I'm in the dealership now (3rd time) having them check it out. Great info, I showed the service guy what to look for. Hopefuly this is the problem and I can get some sleep at night!

[gtc352]

Yep. I was the muffler baffles. They are ordering a new exhaust for me. Should be in this week. All covered by the warranty. Thanks for the post VENICE17517!

[Silver Ice Man]

I have a similar rattle but more at low speeds (almost stopped) or when reversing and it sounds like it is right under the tranny??
Could this be a heatsheild possibly?
Thanx for any advice.

[ckaram]

Had the same noise on my 2LT. Then it just disappeared, right after 2 trips to the dealer. The mechanic could replicate the noise and moved some of the heat shields slightly. I assumed that did the trick....

Now it's back again after nothing for about 3 months. Hmmmm. Wonder if it applies to the V6 too. Noise is right under the trans, very faint and slows down/speeds up with the car's movement.

[Wvallediego]

Is this the noise you hear when you are decelerating on gear? The noise that almost sounds like your car is running too rich?

[don0fthedead]

So I had my car taken in for this, they replaced my exhaust. I previously had this sort of high-pitch clicking noise that would happen when I'd let off the accelerator and continue for a few seconds. It never happened when the car was at a stand still, and was hardly noticeable at first. If the radio was on or even if the AC was on, if you weren't specifically listening for it, you probably wouldn't hear it.

Once I heard it the first time though, it was really bugging me. Now, with the newer stock exhaust, the car sounds fine!

[Angrybird 12]

I developed one on my Saturn Sky, it would happen only at certian RPMS also and found out a piece of gravel had gotten caught between the heat shield and the body, and sometimes it would sound like the whole underneath of the car was going to fall out... Scared the crap out of me...

[dpetramale]

I seem to hear a similar Rattle/vibration when I down shift or the engine strains a little before I down shift to pickup speed. Temperature doesn't seem to be a factor. Sometimes starting off in first gear i hear the rattle/ vibration. I have a Jewl Red 2SS. Dose this seem to be the same asyou hear. I also don't like leaving my car at the dealer. I'm hoping when I go in I can get a mechanic to ride with me to hear. I don't like leaving my car at the dealer. Hopefully I can get a mechanic to ride with me to hear it. How do you guys feel about leaving your cars?

[cajun2010]

My rattling sounds like metal tapping, almost if something is loose, but its a pain in the ass, and kind of embarrasing!
dealership didnt find anything, but i added Flowmaster system and resonated x-pipe, so dont think they are changing my exhaust anytime soon.

[jtzako]

Take a look under the center of the car, there is a metal cross brace there. Try taking that off and see if the rattle goes away. (in my case my exhaust was hitting/rattleing on that) Dont leave it off of course, since it needs to be there, but it is a good way to test.