'15 Tahoe rumble

[mickey5]

Hello folks, I'm a newby and am happy to have found you. I recently traded my '07 Tahoe LT on a new '15 LT. What a disappointment! One week after taking delivery I drove from the Jersey Shore to Sarasota Fl down I-95. What I noticed was a drone/rumble in V4 mode that was constant at 60-70 MPH. It drove us nuts 8 hours a day. Sounded like bees buzzing around my ears. It stayed in V4 mode more than half the time on the straight, flat interstate.

When we got home we immediately took it in to the dealership and was told it was"performing as designed". Opened up a file with Chevy Customer Support who arranged to have a zone manager meet me at the dealership. He was driving the same Tahoe and model as me and agreed with my problem but advised there was nothing to be done as it was designed that way.

When asked why I was told it was for better gas mileage in V4 mode. I advised I didn't spend $60K for a cuople of MPG over my '07. There was no reply.

Any of you out there that has the same problem and what are you doing about it? How about tuning it out? Eliminate or reduce V4 mode?

 

[wblakeney]

I can set the info screen so I can see if it is V4 or V8 mode. At freeway speeds, I cannot tell when it switches back and forth. Either by sound or feel.

 

[amtronic1]

On my 2013 Tahoe there is no drone or rumble in V4 mode. Since what that is is a harmonic, possibly you could simply re-hang the exhaust slightly differently to see if that changes the resonanant frequency. Loosen all the exhaust brackets, move them slightly, then re-tighten.

 

[stealibg]

When asked why I was told it was for better gas mileage in V4 mode. I advised I didn't spend $60K for a cuople of MPG over my '07. There was no reply.

Any of you out there that has the same problem and what are you doing about it? How about tuning it out? Eliminate or reduce V4 mode?

What.... type of MPG are you seeing? I have not experienced that, actually going on a few hour trip today and back... I will listen and pay attention.

I drove mine about an hour out of town last weekend and the mpg i got was impressive around 21/22.... What model do you have? LS/LT/LTZ?

I heard rumors of being able to tune the 4cl out, but unsure what impact that would have if any long term...

 

[mickey5]

What.... type of MPG are you seeing? I have not experienced that, actually going on a few hour trip today and back... I will listen and pay attention.

I drove mine about an hour out of town last weekend and the mpg i got was impressive around 21/22.... What model do you have? LS/LT/LTZ?

I heard rumors of being able to tune the 4cl out, but unsure what impact that would have if any long term...

I have a '15 LT. Gas mileage is about15 around town and 22-23 on the interstate with the cruise on. on I-95 from Jersey to Sarasota, Fl which is straight and flat I got 25+ for the 1200 miles. In the '07 for the same trip I got 21.

Some one over on the Corvette forum indicated that if you get a tune it will void the warranty. I haven't tried it yet but was also told that you may be able to lock into V8 mode by shifting into manual mode. will advise if this works.

 

[stealibg]

Some one over on the Corvette forum indicated that if you get a tune it will void the warranty. I haven't tried it yet but was also told that you may be able to lock into V8 mode by shifting into manual mode. will advise if this works.

Tell you what, I am going on a 200 mile or so trip here in about 45 minutes, I will test the manual theory and report back accordingly.

I am far from interested in a tune that would void my warranty.:Whoa:

 

[stealibg]

So on my way home to pickup the family I tested this.... No dice on manual and it locking into v8

 

[wblakeney]

The change between V4 and V8 should be imperceptible, sounds like there is some else going on.

 

[mickey5]

The change between V4 and V8 should be imperceptible, sounds like there is some else going on.

My '07 and the '15 both shifted back and forth with no perceptable change except the '15 has a rumble/drone in V4. It immediately disappears if you slightly press the throttle to shift into V8 mode. Mechanically the shifts are seamless.

When I first brought this up to the dealer he immediatey brought out another new '15 from his inventory and it had the same rumble when I test drove it.

 

[wblakeney]

This still makes me wonder. I have driven on freeways where it is constantly shifting back and forth from V4 and V8 because of overpasses. If I didn't have it on Trip A or B where I could see the mode, I would not know when it changed.

 

[mickey5]

I now have 6000 miles on the '15 and it still rumbles away in V4. I agree that you cant feel the 4-8-4 shifting but I sure can hear it. Chevy is not interested in talking to me about this problem. My last telecon was several weeks ago when I requested a tech person call me to discuss but I've not heard a thing. Does anyone with a '15 have this same problem?

 

[stealibg]

I have over 2k Miles on my tahoe now, I can hear the noise and I spoke with my service dept mgr about this he said nothing they can do unless GM wants to add a flex pipe or something to reduce the noise when in 4Cl

 

[mickey5]

Your comment is the first positive idea someone mentioned on how to fix the problem. Could you provide some more info on where to put the flex pipe?

 

[stealibg]

no I cannot speak on that, but I will be GLAD to give you the dealership information and be the guinea pig on such tests...I will try to get ahold of him too, he has other pending information

Stonebriar Chevy - Frisco Texas. Service dept Manager Jon if you want to personally reach out to him my last name is Ketcham he should remember me very easily been a long time customer and bitch about the car washers all the time

 

[wblakeney]

This is from a 2010 post on another forum and goes back to 2007 GM models with active fuel management. Why I don't feel or hear anything, I don't know. I have the chrome exhaust extension but don't know why that would make a difference

Some customers may comment on a change in the exhaust note or tone when an Active Fuel Management System equipped engine is in 3 or 4 cylinder mode. Some drivers may also notice a very slight vibration in either the accelerator pedal, floor pan and/or the steering wheel. This is a normal condition for Active Fuel Management System equipped vehicles and no repairs should be attempted.

Customer Information on Active Fuel Management
When the Active Fuel Management System is enabled, physical changes take place within the engine that allow it to run as a 3 or 4 cylinder motor with accompanying additional fuel savings. The change in exhaust tone is expected as all sound from the exhaust is the result of combustion in the engine. The ability to perceive these changes in sound are kept to very minimal levels as the Active Fuel Management System is only activated during steady state/near steady state driving or during coast down. In both of these situations, the load on the engine is minimal and general exhaust volume (sound) is low.

 

[stealibg]

This is from a 2010 post on another forum and goes back to 2007 GM models with active fuel management. Why I don't feel or hear anything, I don't know. I have the chrome exhaust extension but don't know why that would make a difference

This is 5 years later, one model change later, and technologically one more advancement in motors.... this is not acceptable and that is strictly my opinion..GM needs to address this as it is noticeable...

 

[cawt0123]

I just got my wife a 2015 LT Tahoe and it has about 1000 miles on it now, I was searching the internet to see if anyone else was having this problem. I noticed the same symptoms you are talking about and it's really obvious when your going around 30-40 mph in V4 mode. This is unacceptable and their should be something that can be done about it by Chevy, I will contact the dealer I bought it from and see what they say but keep everyone informed on what you guys find out.

 

[mickey5]

I just got my wife a 2015 LT Tahoe and it has about 1000 miles on it now, I was searching the internet to see if anyone else was having this problem. I noticed the same symptoms you are talking about and it's really obvious when your going around 30-40 mph in V4 mode. This is unacceptable and their should be something that can be done about it by Chevy, I will contact the dealer I bought it from and see what they say but keep everyone informed on what you guys find out.

I keep hammering on my dealer about this problem with no resolution. I think Chevy is using the time honored technique of just don't pay any attention to the problem and they'll eventually go away.

The odd thing about this is that my'07 never made any droning/rumbling when shifting from 8 to 4 cyl. With 100 more HP in the'15 you'd think it wouldn't be working as hard. The noise sounds like its lugging the engine in V4

 

[Luhu]

We drove my '15 LTZ 3 hours home immediately after purchase, and we didn't hear any difference between V4 and V8.

 

[mickey5]

This drone/rumble problem is so widespread in the 5.3 liter Tahoe,Suburban,Silverado and Camaro that a company I just found is mfg a plug in device that locks the motor in V8 mode eliminating the V4 noise problem. It plugs into the OBD II port under the dash and does not change the computer or void the warranty cause when you unplug it the V4 function returns to normal. Gas mileage change is minimal according to their website user comments. The name is Range Technology...Google it and read if interested. To me it sounds like just what is needed even if GM won't comment.