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I just got a new 2018 Redline yesterday (493 miles). Today with 2 passengers, it started making a loud noise around 40mph at 2000 rpm. If I lift the throttle it gets 10 times worse. I can feel vibrations. It seems like the tranny wants to shift to the next gear but it a bit stuck. This is under light acceleration. If I give it more throttle, eventually it shifts, the rpm drops and the noise goes away. Under deceleration, it just gets a lot louder and more vibration then goes away as the rpm drops.

I read about similar occurrences on the Camaro and Malibu sites.

I will be following up with the dealer and will report back. I was surprised there were no other Traverse owners experiencing this. Figured I should bring it up.


-Rick
 

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Rick,

I have the same exact issue. Some times at higher speeds, but still at 2000RPMs. It seem like it wants to sift gears but doesn’t. I will be calling the dealership to set up an appointment also. Please let me know what you hear.
 

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Any word on this? Similar sounding issue with Traverse we bought in May and with the loaner on the second trip back to dealership. Noise is loud enough and right frequency to hurt my ears. Seems to be worse with around 700-800 lbs of passengers in it.
 

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Back to the dealer today and he thinks it is an issue with the exhaust. Relative has same model and it doesn't do it on hers.
Tried to capture sound but, iPhone can't seem to pick up that low of a frequency. Feels almost like somebody is in car next to you with bass going at a constant pitch. Shakes your insides.
 

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All exhausts make a noise at the harmonic point under load, even with the radio off I can barely hear it on mine. And just had my hearing checked and it's normal without any assistance.



Just a guess, assuming no exhaust leakage noise from the flexible fitting at the exhaust manifold to engine pipes:



All Traverse exhaust systems are not equal...same engine pipes, cats, damper, muffler and resonators, but different finishers and slight variance in manufacture and the way they are installed. Finishers on the Premier are flat, rectangular and extend past the bumper, exhaust goes in a straight line rearward from the vehicle....other lines are shaped like a "bell" directing the sound 360 outward toward the pavement and rear hatch instead of straight out the back. Lengths will vary slightly and 1" could make the difference between the harmonic waves getting past the bumper or hitting the bumper, and maybe some vibrations from the rear of the "bell", directed back under the chassis amplifying the sound.
 

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Wondering if you ever had this issue resolved? We recently have had our 2018 Traverse looked at due to the same issue around 2000RPM'S having a very loud humming noise. We also notice that it was with more weight in the car.
 

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Wondering if you ever had this issue resolved? We recently have had our 2018 Traverse looked at due to the same issue around 2000RPM'S having a very loud humming noise. We also notice that it was with more weight in the car.

There's another post on this with more detail. One dealer was addressing it by replacing the ANC, (automatic noise cancellation system). I posted a link to a GM site detailing a problem with the microphone placement/installation in the system.


https://sandyblogs.com/techlink/?p=10528


Possible because if there is a defect in mic placement or the system it will increase noise levels at certain frequencies instead of cancelling them. Simple quick test, pull the RDO fuse which will disable the radio which remains ON all the time (irrespective of button control) broadcasting the ANC signal. If removing the fuse solves the problem, it is either the ANC module or microphone.




Just for the helluvit I pulled my RDO fuse and the engine then seemed much louder under load at the 2000 harmonic ..... replaced the fuse and it was once again quieter...............proving the system actually works on mine.
 

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Wondering if you ever had this issue resolved? We recently have had our 2018 Traverse looked at due to the same issue around 2000RPM'S having a very loud humming noise. We also notice that it was with more weight in the car.
Our 2019 traverse does same thing at 2000 rpms going up hill with full load in car...when it drops down a gear it has a very loud exhaust drone noise...very aggravating...have been to dealership once but couldn't reproduce sound in the town..we will have to go back and get it on the interstate!

Sent from my SM-G955U using Tapatalk
 

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I wonder if the transmission become too lazy to switch gear when the engine gets too loaded. Just like when you have a standard shift transmission and you leave it too long before the engine needs a lower gears to pump up the R.P.M? You get the drone effect
 

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I wonder if the transmission become too lazy to switch gear when the engine gets too loaded. Just like when you have a standard shift transmission and you leave it too long before the engine needs a lower gears to pump up the R.P.M? You get the drone effect

The noise is exactly what you would hear in a manual tranny when under load because the because the positive action Sprag clutch and high efficiency torque convertor make it behave more like a positive engagement tranny, especially noticed in the lower gears.......hence a 29+ mpg highway with a 310 hp engine capable of 0-60 in low-mid 6 secs. But the engine is not lugging as it would do deadfooting in a manual running at a too low rpm that needs to be downshifted to a lower gear....if that was the case the engine rpms would continue to slowly drop and the ECU would force a downshift .....problem seems to be that the engine has enough power in the existing gear, but the rpm is at a bad harmonic for the engine transplanted in the newer lighter and different construction body. Force a downshift by smashing the accelerator or throw into "L" and hit the (-) to drop 1 gear and no more noise at the higher rpm.


I'm beginning the think that the active noise cancellation (ANC) system is put there on purpose on the '18+ Traverse' (and other new GM body designs) not dues to the generosity of GM but because it is necessary to mask unpleasant noise characteristics of the lighter unitbody - engine - mulitspeed tranny designs. Why else would GM include it standard in all Traverse lines and not even list it as a feature in the specs? I thought the ceiling mic was there for the OnStar/Voice command systems until I saw in a GM pub that it is also part of the ANC system. Efficiency of the system may be affected by the number of speakers in the model, fader control positions and ranges of individual human hearing.. I had pulled the amplifier fuse to defeat the system and can confirm that the Traverse becomes much noisier without it.....it doesn't eliminate the noise, just masks it.
 

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Do me a favor. When you hear the noise, especially when you are decelerating. If you have an AWD model, switch it into AWD mode and see if the noise goes away.
 

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Hello! Yes Indeed - same issue on 2019 traverse as I posted yesterday - 2000 rpm. I will have the dealer look at the ANC unit and exhaust. Sounds like this is a known issue. The noise happens with either cruise control on or off. Coolant Temp remained the same around 220 degrees, seemed like it happened every time the car went down or up and sort of "hill" - even the slightest incline or decline. Thanks!
 

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Dealer replaced Amp which apparently also has the ANC. still making the racket at 2100 rpms. Seems to have something to do with the passenger seat being occupied.
 

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Dealer replaced Amp which apparently also has the ANC. still making the racket at 2100 rpms. Seems to have something to do with the passenger seat being occupied.

I'll defer on comments related to passenger size and weight and focus on the acoustics. Evidently the passenger is reflecting the counterwaves such that they are not cancelling noise at certain frequencies/levels.....might be able to determine by wrapping the passenger in a thick wool blanket or alternatively aluminum foil........glad mine doesn't do it because it would take a helluva lot more convincing for the wife to participate trying this than it was to have her roll a stuffed teddy bear in front of the 10 mph vehicle to test the auto braking system (auto-braking dependability my a$$, RIP teddy)
 

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Hello! Yes Indeed - same issue on 2019 traverse as I posted yesterday - 2000 rpm. I will have the dealer look at the ANC unit and exhaust. Sounds like this is a known issue. The noise happens with either cruise control on or off. Coolant Temp remained the same around 220 degrees, seemed like it happened every time the car went down or up and sort of "hill" - even the slightest incline or decline. Thanks!
Ours does the same thing we have a 2019 traverse...loaded down and shifting down a gear going up a hill around 2100 rpm we get a loud exhaust drone noise until it switches gears

Sent from my SM-G955U using Tapatalk
 

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I guess we can all agree that all cars with a gasoline engine have rotary harmonics and exhaust noise which generate resonance noise at rpms specific to each engine. Weight is a determinate factor in loading the engine but speaker placement may be more important than the the weight of the passenger.


Condition with the gen2s is likely aggravated by the 25 hp boost, 3 additional closer ratio gears in the tranny, lower gauge lighter weight bodies, and software programming to minimize downshifting to increase CAFE mileages. Likely the increased 310h.p. is sufficient to prevent engine and forced downshifting under load than the previous 285 h.p. wide ratio 6 speeds, with less lugging at the expense of holding the engine at the dreaded 2000/2100 rpm V6 resonance point. You don't get 28+ mpg with a 310 hp engine capable of 0-60 mph in mid 6 sec without some trade off. The installation of a stock ANC system is likely GM's attempt to counteract the inherent design limitations transmitting resonance noise.



The ANC system in mine does work in masking this resonance.....evidenced by it becoming noticeably louder when I disable it by pulling the (RDO) amplifier fuse. Additionally, there may be a difference in effectiveness of the system based upon models and interior rear seating placement and type of surface coverings. The Bose systems use 9 speakers and a more powerful amplifier and subwoofer capable of generating lower frequencies instead of the base 6 speaker system. The placement of the rear D pillar speakers and in particular the center dash speaker located between the driver and passenger may have increased masking capability.



Seems, if the dealer screwing around with the ANC system and microphone placements cannot lower/cancel the noise....then not much else you can do.
.
 

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Brian Narkinsky, Yes, same here: I am a 135 lb female, there is never any noise when it's just me driving, but as soon as my husband 260 lb + male gets in passenger seat the noise starts (in particular on long trips after car is warm and have luggage and 3 kids in the back). The sound goes away if he's driving, and I am in the passenger seat. Hence, I believe this noise is directly related to heavy weights SPECIFIC to the PASSENGER seat. No clue why but would like to know. I will keep following this thread!
 
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