V4 to V8 'Squeak'

tenthousanddays · June 29, 2016

Now that it's warm out, I've been driving with the windows down. I started to notice a 'squeak' whenever I would hit the gas a bit. After monitoring for a bit I noticed it specifically occurs when switching out of AFM, V4 to V8. It's a pretty loud sound, and kind of drives me nuts. Has anyone else experienced this? I'm trying to decide whether or not it's worth it to take it to the dealer to look at, it doesn't feel like there's any issue mechanically - just an annoying sound.

Edited June 29, 2016 by tenthousanddays

lagerman72 · June 29, 2016

I think some others have had this, I know I have it and try to tune it out.

http://www.gm-trucks.com/forums/topic/172013-squeak-when-throttle-is-applied/

GMCustomerService · June 30, 2016

Good morning tenthousanddays,

I’m sorry to hear that you are experiencing a noise concern in your engine and can understand how this squeak can be frustrating. I recognize that at this time you are reaching out to other forum members to see if anyone else is experiencing the same symptoms. However, I would be more than happy to offer my assistance if you choose to work with a dealership. Please private message me with more details if you would like my support.

All the best,

Julianne M.

GM Customer Care

Now that it's warm out, I've been driving with the windows down. I started to notice a 'squeak' whenever I would hit the gas a bit. After monitoring for a bit I noticed it specifically occurs when switching out of AFM, V4 to V8. It's a pretty loud sound, and kind of drives me nuts. Has anyone else experienced this? I'm trying to decide whether or not it's worth it to take it to the dealer to look at, it doesn't feel like there's any issue mechanically - just an annoying sound.

v2500guy · July 13, 2016

mine is in there for this now. Its been a week. They have replaced the exhaust, lifters, and now a cam shaft is on order.

Edited July 13, 2016 by v2500guy

Cohen · July 13, 2016

Same thing happened to mine but was constant, drove me nuts. Sounded like the rear end bearings were bad. Ended up being the flapper valve, dealer replaced it with a new one.

EFLine · July 13, 2016

I posted about this a while ago, consensus was the flapper valve in the exhaust

http://www.gm-trucks.com/forums/topic/181503-whistle-out-of-v4/?do=findComment&comment=1737266

Brian2015 · July 14, 2016

I have the same exact squeak when AFM cylinder deactivation returns back to V8 mode. I made an appointment at my local dealer (Sutliff Chevrolet- Harrisburg PA) for a tail gate handle adjustment and the squeak. The service representative basically told me there is nothing they can do about the squeak. I bothers me so much I can't drive with the windows down.

Is there an updated exhaust system or flapper valve?

Tiger_993 · July 14, 2016

Mine was at the dealer earlier this week for this issue of a squeak when going from V4 to V8 mode. They diagnosed it as coming from the flapper valve and immediately ordered a new exhaust which will be in next week. My service guys say the replacement exhaust has an updated part number so they believe the flapper valve has been redesigned.

v2500guy · July 14, 2016

I hope yall have better luck than I do.

v2500guy · July 19, 2016

Did you get new exhaust put on? Mine is STILL at the dealer.

agency12 · July 19, 2016

I've had my 2015 in 3 times for this same issue. First time they added high temp lube to the flapper valve. This worked for a couple of day's and then the squeak came back. Took it back at my next service interval and they replaced the entire exhaust system with the so called updated part number for the flapper valve. The noise went away but returned 2 months later and when I took it back they stated that GM was aware of the issue but they do not have a fix for it yet. This is the same response I got for the leaf spring noise! They said the only direction that GM gave them is to use the high temp lube on the flapper until a fix was released. WTF!!!

tuckersnator · July 19, 2016

Mine too. I hate V4 mode anyway and bought the Range AFM disable device. No more metallic "tink" for me!

mabran · July 19, 2016

My 2015 LTZ did the squeak going from 4 to 8cyl mode. Weirdly enough after 12k or so it stopped doing it and hasn't squeaked since and I have just under 30k on it. Other than that the truck has been bulletproof no issues with anything.

v2500guy · July 19, 2016

I just hope I have no issues going forward since they have been screwing around in the motor

bc-chris · July 21, 2016

i bought my 2014 silverado a little over a month ago and only noticed the squeak after the weather cooled down a bit and i was driving with the windows down.

i found the 'squeak' threads and thought, 'for about a buck and less than 5 minutes i might as well try keeping the flapper open.'

annnnd... the problem is solved!