2014 Sierra humming noise

VMaxtastic · February 13, 2014

I have the same noise with mine. Haven't had a chance to take it in yet though.

Threeblacklabman · March 19, 2014

Hi,

I thought I would add my recent experience regarding the same 2014 Sierra Humming noise.

With my recent purchase of a new 2014 Sierra cc/Z/71, it also has the rhythmic hum noise predominantly at 65 mph.

Local GMC dealer has confirmed the noise. They have swapped wheels/tires, driveshaft from a duplicate unit and rhythmic hum at 65 is still there.

I requested they open a tech support case,

Case# 71-1279990621.

"They had no repairs for this case, advised to duplicate to a like truck and use chassis ears. They could not isolate the noise with the chassis ears.

Service spoke with Gary Kilmer at TAC, Gary stated said people have tried to fix this noise and have been unsuccessful!

Said that the gear ratio seems to change where the noise is heard(speed range). Gary recommends no repair's to be made, Normal truck harmonics causing faint hum!!"

FYI, I was in a 2014 sierra cc 2wd loaner for two weeks and it did not have that noise, only 4wd units from my understanding.

Now that I am totally frustrated with GM, Gary Kilmer/ TAC and the comment "normal" has led to this post.

Going back for two more times, then off to court to file a Texas lemon law.

GM,

Am I to believe that most related post with a very similar noise , rhythmic hum, hum, hum noise predominantly at 65 mph , that is Normal??

Good luck with that!!

gSwift · March 19, 2014

I've got a 2014 Sierra as well that's making the same noise. I originally though mine was due to the 6" suspension lift and 35's that came on the truck. But after reading the comments here, it seems as if its a common occurrence...lifted or not.

jcchevy · July 26, 2014

Sound happens under power and while coasting. Doesn't matter what gear I am in.

Goes like this.

XXXXXXXX__________XXXXXXX________XXXXXXXX________XXXXXXXX

XXXX=hum and lasts about 1 sec with 1sec pauses in between. Really weird.

Update on the humming noise. If I shift it to 4x4 auto, the noise disappears. If I shift it back to 2x4 noise gradually comes back.

Curious if you guys (C6 Doberman, Oli4, RM4665, UCR, or gSwift) have any new updates on this. Oil4, you described it perfect previously and when i put it in 4x4 auto, it disappears as well and when i go back to 2x4, gradually comes back.

Like C6 Doberman, i originally thought my 6" lift 35" tires was part of the issue and the dealer & dealer accessories have looked at the issue and contribute it to "normal road tire/differential noise".

The thing is this didn't start until the 4000 mile mark, and i had the lift and bigger tires put on around 3000 miles and the truck was quiet/smooth as silk.

So something "broke down" around the 4000 mile mark causing this annoying "RUMBLE STRIP VIBRATION" feeling, starts hardly noticeable around 58 and continues to get louder (predominantly around 65) and goes away completely at 72mph or faster.

By the way, i since changed out the aggressive 35" tires with much tamer Open country all terrains, which didn't change the noise one bit, and can actually hear it more now because the new tires are so quiet on the road compared to previous ones.

I have posted this info before on the "novel vibration" thread going on, but most of that is completely different than what I (we) are experiencing. I do believe this issue would have come about if i left the truck stock as well , after seeing so many other posts with stock vehicles experiencing and being able to describe it.

I honestly am waiting for something to break and wish it would do it soon, or hoping they find some common issue and i can print out a technical bulletin to give to the service dept for proof of a fix.

Oli4 · July 26, 2014

I'm 27000km in and the noise is still there. My dealership made a note of it in my file plus has documented and verified the sound as well. So it's not hear say from me. They also road tested another vehicle and it had it too.

IMO this is NOT normal road/trans noise. This is a harmonic. It might be harmless it might not. All I can tell it still annoys the crap out of me.

I'm like you at this point. I'm waiting for it to break on me.

jcchevy · July 27, 2014

Thanks for that update Oli4, also you been helpful more then once as looking back you stated the below.

Same here. But. Here's an update. It goes away when trans temps reach normal operating temperatures 90C. Did a long trip over the weekend and it went away. It's back now though.

I have noticed that before, because 95% of my driving is trips to the town on the hwy (55mph speed limit) for 8 miles, I hear this rumble strip cycle vibration the whole time as I don't think the trans even gets to oper temp by that time.

So today went to a city nearby with the wife for some shopping (50 mile trip / 65mph freeway). (I traveled 72mph entire way as the hum goes away then and is smooth as silk). After the 50 miles (trans temp was 200F or so) guess what, the noise was 100% gone regardless going 55 all the way to 71.

And after the truck sat awhile (shopping) and the temp was under its 170F or so, the dam noise/hum was back. I do believe we are on to something. Either transfer case or something to do with the material inside the driveshaft that suppose to help dampen the noise or some crap is the real culprit. And honestly not sure if it has anything do with driveshaft unless the driveshaft is heating up from the trans as well resulting in a temp fix to the problem.

So with that evidence and testing its either Transfer case/transmission or drive shaft. (front shaft was removed for testing once and noise was still there, according to dealer service rep).

I am thinking the (TCM or some other component) went to semi-junk-degraded state after 3000 miles or so and after it heats up to 200F/normal op temp like you stated and we both proved, its (vibration dampener/torque converter/harmonic balancer or whatever) is working as it should.

Unfortunately I guess we have to be smarter then the GM engineers who can't figure this out to resolve it. I am open to all ideas, I am an IT engineer, wish I could work directly with a GM engineer and troubleshoot this directly as i am sure we would figure it out. But going through dealer, service rep, TAC , back to accessories (blame it on them because it has lift/bigger tires) causes too much middle man to get something like this resolved quickly (IMO).

Guess we will have to work on installing a transmission block heater (like the engine) and getting it to 200F before we drive it so our trucks drive like new again ;)

Edited July 27, 2014 by GM-GUY

DRS 95 Silverado · July 27, 2014

Mine does it also. I posted about it in a another thread here. It's not bad but you notice it. I mentioned to service manager. I thought maybe it was coming from the exhaust system. Don't notice on a short trip to town but when we go on our 30 - 35 mile trip to shop on a rolling hills type road I hear it some. Comes and goes.

warmie@245 · July 30, 2014

I posted about the same loud humming noise above 45 mph earlier. I met with the GM zone mgr two weeks ago and he contacted GM engineers. I was told it was an issue they were aware of and they had a fix for it. They are sending out a new Yoke and universal joint and have advised that that is the fix. Still haven't got the parts in. This is happening to my 2014 Silverado 5.3 with 3.42 rears.

fondupot · July 30, 2014

My last car did this when it was brand new (2012 Kia Optima Turbo). Went away after 5k miles.

jcchevy · July 30, 2014

Thanks @warmie@245 for the update, I do think your humming is a little different then Oli4, mine and couple hours per your previous statement.

"Humming starts at about 45 mph under power and stops when I take foot off of accelerator"

Not to say its not same fix though. Regardless of putting it in neutral coasting etc...our rumble strip vibration still occurs. For us (Oli4 and couple others) we narrowed it down to - as long as the transmission temperature is under 190 degrees the running over rumble strips feel (cycle on / off every other second) is there. Once the transmission is at 190/200 the dam thing is smooth as can be. And the closer it gets to the 190 degree mark the quieter it becomes. So something is expanding in the transfer case /transmission etc that eventually produces a tight seal of some sort (yoke/torque converter etc.) resolving the "loose" component causing the rumble strip vibrations.

Why else would there be a magic 190 degree temperature change affect it that much.

Either way, let us know your outcome with those replacement parts. I am keeping track of potential culprit items that could easily be the issue.

Rollcenter · August 29, 2014

I took delivery of a new Z-71 5.3, short bed, crew cab this week, got a lil over 500 miles on it and I have the EXACT same issue, a rhythmic on-off vibration in about 1 second intervals. I'm going to take it back to the dealer but has a "fix" came from GM yet?

jcchevy · August 29, 2014

Welcome to the forum @Rollcenter. You have 4x4? Does the rhythmic (we like to call it rumble strip feel/sound) go away when your transmission reaches optimum temperature (.i.e 190/200F degrees)? Several of us can reproduce that. You should give that a try (it takes about 18 miles/in 70 degree weather of driving to actually get it to that temperature in my experience. Mine will be going back to the dealer shortly and they can't cough it up to "normal road noise" now that I can replicate resolving the issue by getting the transmission to its optimum temp. There is definitely something that wore out/bad part in one of the areas of the drivetrain causing this. Mine didn't start till around the 4K miles mark FWIW.

Rollcenter · August 29, 2014

Mine does it no matter what temp the trans is at. I traveled 127 miles yesterday averaging 60-75 mph and it did it pretty much constant. It's a slight rhythmic on-off vibration that s felt in my butt and steering wheel, I "may" even be able to hear it.

My truck is a 4x4 truck..

stevev · September 2, 2014

Wasn't sure to post here or start another thread.

I have some type of humming or drone noise that sounds like it's coming from the front of the truck, it doesn't occur all the time but I only notice it at lower speeds (25 to 35mph) and under a slight engine load like going up a hill. I tried switching to 4x4 Auto and the noise still occurs. It can last for several seconds. When I hear the noise, it immediately goes away if I take my foot off the gas pedal. Again it sounds like it's in front of me and I don't feel any vibrations in the floor, pedal, or steering wheel. Any thoughts? Only have 600 miles on the truck so far, hoping it goes away after it breaks in some more.

(2014 Sierra CCSB, 4x4, 5.3v8, 3.42 gears)

Edited September 2, 2014 by stevev

stevev · September 3, 2014

I have some type of humming or drone noise that sounds like it's coming from the front of the truck, it doesn't occur all the time but I only notice it at lower speeds (25 to 35mph) and under a slight engine load like going up a hill.

well I clamped open the exhaust valve and have been driving around today, and I haven't noticed the noise yet. Hopefully I fixed it and will leave that exhaust valve clamped open permanently like many others have done on here.