Exhaust leak on my 2021 Chevy Traverse

[JTK]

The general bit me again..

About a week ago I noticed our Traverse was loud on a cold start when I was brushing snow off of it for my darling bride. I asked if she noticed it was loud and for how long. "Maybe a few days" she said. The exhaust leak is about mid way from front to back on the vehicle. Seems too far back to be the typical front pipe bracket breakage that you hear so much about on the 2018-2023. So much so that TSBs exist for that issue.

It has been snowing pretty much non stop for a week, so between that and my work schedule, I wasn't able to take a peek at it until today. I laid a piece of cardboard down and slid part way under. I have a large exhaust leak going on at the two bolt flange, downstream of the center muffler / resonator. The flange looks crusty, but it's appears intact and is still bolted together. I don't know if the gasket blew out or what's going on there.

I made an appointment with a shop I like that is less than 2 miles from my house. If it's not a simple gasket issue and the flange is junk, I'm hoping he can do a repair with a coupling and delete the flange joint. Exhaust system problems on a 4yr old 47K mile vehicle is disappointing for sure. I haven't had exhaust issues this early in a vehicle's life in over 30yrs.

 

[TCL]

Could she have hit a chuck of frozen ice/snow in the road and knocked it loose?

 

[THORROMIG]

I was wandering the same, was something hit?

 

[JTK]

No signs of impacts or rubbing against anything. These vehicles have decent ground clearance. My bratwurst shaped self can fit under most it with the wheels on the ground.

 

[Slick3914]

Curious to hear the final outcome

 

[Trav]

Putting a new flange on is no big deal, if you need to replace the back part of the system at some point it will bolt right up.
This place has a lot of them. If you want to eliminate the flange use SS pipe with band clamps.

https://www.bearriverconverters.store/collections/oval-universal-quickfix-repair-kits

Pipe and clamps..

https://www.verociousmotorsports.co...c3wAnPGxw38F199pA27cDgH8SECO9YhJDSgsen&page=1

https://www.verociousmotorsports.com/accuseal-exhaust-clamps

 

[supton]

That's a bummer. Unexpected but sometimes you get by the random "this should never have happened... but it just did" thing.

 

[JTK]

Turns out the bolts were rotted apart on that flange downstream of the front resonator. New gasket, new bolts, nuts and lock washers. $23 parts, $76 labor and $8.66 tax for $107.66 total. She's fixed. I really should have thrown her up on ramps and took a better look.

 

[Dave Sherman]

Weird, my Ram had the same thing happen this year. Started getting noticeably throaty on acceleration, then eventually got to where it was loud at idle. Got underneath, and there's about a 1/16" gap at the union between the y-pipe and the cat. Almost like the bolts had just gradually worked their way loose. Went to turn one, and it snapped like a twig. Took it to a shop, they drilled out the bolts, cut off the blind nuts, and just put stainless nuts and bolts on, about $150. Said they've seen a few of those.

 

[andrew_j]

Turns out the bolts were rotted apart on that flange downstream of the front resonator. New gasket, new bolts, nuts and lock washers. $23 parts, $76 labor and $8.66 tax for $107.66 total. She's fixed. I really should have thrown her up on ramps and took a better look.

Good for 4 years ! Hopefully better quality parts installed. Appears GM is buying from the aftermarket suppliers off eBay maybe.

 

[supton]

As much as I want to say, they should last far longer than that, a repair today that isn't a kilobuck... a quick repair and back to new, and not wallet draining? hard to complain.

 

[KrisZ]

Good to hear it was a cheap fix. Is there better hardware available for your model than OEM? May be worth looking into, otherwise you at least know the schedule now

 

[JTK]

Good to hear it was a cheap fix. Is there better hardware available for your model than OEM? May be worth looking into, otherwise you at least know the schedule now

I didn't have a chance to talk with him, but I'm sure he used what he had and it's probably not stainless steal or anything fancy. We had 3ft of snow fall between Weds and Friday this week and I haven't been able to take a good look underneath the beast. FWIW, his labor rate is $95/hr.

 

[supton]

I didn't have a chance to talk with him, but I'm sure he used what he had and it's probably not stainless steal or anything fancy. We had 3ft of snow fall between Weds and Friday this week and I haven't been able to take a good look underneath the beast. FWIW, his labor rate is $95/hr.

If it wasn't SS, then you know it'll have to be redone in what 3 years? may or may not be better steel than OEM. Then again, if you could time it just right, perhaps you can wait for inspection and have him redo the job while it's on the lift.

 

[eljefino]

You got a good deal at around a hundo, can't get anything for that money anymore.

I was wondering if it could count as part of the federal catalytic converter warranty. Save your receipt in case there's a recall later.

 

[JTK]

If it wasn't SS, then you know it'll have to be redone in what 3 years? may or may not be better steel than OEM. Then again, if you could time it just right, perhaps you can wait for inspection and have him redo the job while it's on the lift.

Nagging exhaust system problems seem to be the bulk of the complaints you hear of with the 2018-2023 Traverse. It's overly complicated IMO. The catalytic converters are bolted directly to the cylinder heads of this 3.6L like most of them are now. No exhaust manifolds. This seems to be working out for most make/models, but this GM 3.6 can form cracks on the outlet elbow of the bank one catalytic converter. You can generally get that covered by the fed emissions warranty. Then there's the front and mid assembly that contains two flex joints that will eventually form pinhole leaks, two "clean up" catalytic converters and a resonator. Most of it is one big assembly (see pic below). This is a $500-600 part. That outlet flange is the one where the bolts rusted apart on mine. Then there's the rear dual muffler assembly that takes you all the way to the rear at a cost of $800.

The small triangular image with the 3 holes to the lower left of the pic below is part of a bracket that joins the two front pipes together (bank 2 front pipe is separate). This bracket can tear away from the pipe to due "poor welds". There is a TSB that covers just the bank 2 pipe in the event this happens and it happens a lot to these.

With the way things are designed today, IMO, there's a lot to be said for a 4cyl or inline engine in terms of "simplifying" the exhaust system. The dual outlets is just plain silly for the bulk of the run of the mill vehicles out there as well.