How do I fix left rear exhaust chatter?

[Hixson]

Morning everyone,

Two weekends ago we finished the build weekend for my car - adding headers, high flow cats, cam. Adding the Stainless Power Headers meant that we needed to play some with the exhaust. For the first week and half or so my car has been flawless and I couldn't have been happier. Engine sounds and runs strong and all was well in the world. In the last few days, I have developed a very annoying exhaust chatter at stop lights and during driving, and today it became quite a bit louder and more frequent. I got to work today and tried to do a quick inspect to see if anything came loose or was touching that I could tell. So far I cannot see anything out of the ordinary.

Does anyone have suggestions for what I can do to verify what the rattle is and how I would go about fixing it?

Would also appreciate some feedback, would this be something that is worth taking to a shop to fix, and if so does anyone have a recommendation of a place that would be a good choice?

Thanks for the help guys. Love the car with all of the new power mods, but they are definitely making my Camaro chatter and that's no Bueno.

[frankwjr]

video...where exactly is the noise coming from? let the car cool, crawl under and start banging...double check bolts, etc...good luck!

peace

[Junior]

When this happened to me (same side), it was the rear most hanger that goes into the rubber mount. It worked it's way back to where it was just about touching a metal cross member. i just worked that side back a bit, and it went away.

[Juiced1]

You're going to have to go through and look for any contact. Let it idle or have someone hold the brake with it in gear if that's the only time it happens and try to pinpoint where it's coming from. After that you'll have to get under the car and start shaking/moving the exhaust around until you can find your source. Sometimes it's just an easy adjustment or sometimes you need to get creative. Maybe bending a piece of the heat shied is required or even putting a small bend/dimple in the exhaust.

[Hixson]

Thanks guys. Just trying to decide if its worth taking an hour to the shop where we can set it on jack stands and get under the car, or if it would be an easy fix for a place like Midas to just charge me $100 or so and get it over with. Hoping it something easy. Its crazy how some loud exhaust chatter can ruin your driving enjoyment lol.


Frank - its the rear left portion of the car. I initially thought it may be the license plate rattling so I bought a dynamat kit to deaden the noise back there. When adjusting the exhaust a couple of weeks ago we noticed rub marks/scratches where the exhaust had been touching the left side of the rear diff housing. It may be doing this again, but I didn't anticipate it to be this as we made sure we made adjustments during the build weekend. The only other guess I have goes along with Junior, maybe the hanger is being a PoS. We had to undo the hanger to get to the diff fill hole when I was changing that out, so maybe dad put it back loose or something? Ill do my best to look during lunch, but will be tough to diagnose by myself in dress clothes in parking lot lol

[Hixson]

called Midas and talked to the guy, hoping it something easy and should be around $100-150 fix

I told them to just go ahead if that's all it will cost so I'm getting it fixed at 1PM. Will report back if its fixed

[WoodBoss]

Originally Posted by frankwjr

video...where exactly is the noise coming from? let the car cool, crawl under and start banging...double check bolts, etc...good luck!

peace

I agree with Frank here. I would not waste my time going to a shop. If you want something done right you will need to do it yourself, especially on performance cars. No short cuts, you need to get under there and check every connection and tighten things up. Look for clearance issues too, Something may have moved from heat cycling the exhaust.

[Abelardoo_12]

It could be the brace that goes diagonally from right behind the door to right behind the diff housing. I dont know any better to explain it lol. Ut the exhaust passes over it with little clearance so if you’ve messed with the exhaust then you might of left it a little lower and that could be causing the exhaust to rub on it.

[Hixson]

Had it checked out at Midas, it was free so thanks guys at Midas.

Says the exhaust was beautifully installed and has no movement or play. He cant imagine its causing the chatter, which we could not reproduce during the time I was there. On my way back to work it chattered again so I went back and showed him the video I recorded of the noise. He said that it is likely the heat shields underneath the car and referred me to a body shop here in town. I guess I will go get it checked out there, I don't know what DIY remedy could fix a heat shield issue

[00 Z/28]

Check that it's not too close to the rear diff. Mine has rattled off that on the left side. Also it can end up touching the rear pinch weld on the body just behind the diffuser.

As for the giant heat shield that runs under the car, rubber mallet to where ever it's touching the exhaust will fix it quick.

[Hixson]

Yeah we check the rear diff everytime this noise pops up. At one point I think it did actually rub some but since we tightened things up and repositioned, its got enough clearance that its a non-issue. I'm really thinking the heat shield is going to be my culprit so I need to look into fixing this. I have read that stuffing some exhaust header wrap works well, but I will consider the mallet as well. Lots of old threads on this heat shield issue but haven't seen any recent one. Anyone have a fix they can pass on?

[xc_SS/RS]

You sure it isn't the muffler? I don't see it mentioned that you have an aftermarket catback and I know the stock mufflers have a tendency to get buzzy once things get old.

Tap the mufflers with a mallet and you might find the noise.

[Hixson]

sorry should clarify ^

I have stainless power headers, connecting to high flow cats, connected to stainless works catback. All exhaust is aftermarket

[Hixson]

here is the video to see if anyone else agrees with the noise diagnosis

https://youtu.be/8t8H3WZbX0U