Sounds like rumble strips
06-22-2017, 11:11 PM
#121
Safety Car
The only real way to get rid of it is to program it out one way or another. 
Last edited by C7/Z06 Man; 02-27-2018 at 01:55 PM.
06-22-2017, 11:33 PM
#122
Pro
Thread Starter
I would arm yourself with the TSB and get the belt replaced. It's a minor 20 minute fix. I did it and it seems to be the fix. I got the GREEN belt.
Last edited by dckotwicki; 06-22-2017 at 11:35 PM.
06-26-2017, 05:23 AM
#123
Melting Slicks
does this happen to 2017 as well?
07-17-2017, 05:26 PM
#124
Instructor
The following users liked this post:
BOBSZ06 (08-16-2017)
08-15-2017, 10:41 PM
#125
Intermediate
I own a 2016 Z06 with 3500 miles on it. Recently went into northern Michigan for a weekend get away. The roads are smoother and quieter with less traffic noise. Some roads have rumble strips imbedded into the side and center of the road to get your attention when you wander left or right. These get your attention big time. During the drive, I began to notice a similar but quieter noise. I began to study the road surface but could find nothing to connect to this noise. I started to look elsewhere for the source and discovered a direct connection to the AFM (active fuel management).
With the cruise control on and on a relatively flat road I began to notice this subtle rumble noise (similar to hitting rumble strips but much quieter) occurring when the engine was in 4 cylinder mode. When it went back to 8 cylinder mode, the noise went away. The noise always happened before returning to 8 cylinder mode. The duration of the noise ranged from 1-2 seconds to several seconds (5-10 seconds) and always disappears once the engine is back to 8 cylinders.
I am not a mechanic and do not know the mechanism that causes the engine AFM to activate, but I wonder if there is something acting up in the system that activates the AFM.
Anyone experience anything like this or have any possible explanation for what is happening?
The engine had the 500 mile oil change at the dealer and again at 1000 miles. Both with Mobil One. Oil level is where it should be and shows 65% oil life.
With the cruise control on and on a relatively flat road I began to notice this subtle rumble noise (similar to hitting rumble strips but much quieter) occurring when the engine was in 4 cylinder mode. When it went back to 8 cylinder mode, the noise went away. The noise always happened before returning to 8 cylinder mode. The duration of the noise ranged from 1-2 seconds to several seconds (5-10 seconds) and always disappears once the engine is back to 8 cylinders.
I am not a mechanic and do not know the mechanism that causes the engine AFM to activate, but I wonder if there is something acting up in the system that activates the AFM.
Anyone experience anything like this or have any possible explanation for what is happening?
The engine had the 500 mile oil change at the dealer and again at 1000 miles. Both with Mobil One. Oil level is where it should be and shows 65% oil life.
08-16-2017, 01:34 AM
#126
Pro
Thread Starter
08-16-2017, 04:41 AM
#127
Advanced
Supercharger belt for me too. Dealer could not find the noise, so I paid for the belt and the install, about $100 total. Belt (Gates K080852RPM) was around $60 on eBay, and install was around $40 at a local shop. Worth it. I couldn't take the noise anymore.
08-16-2017, 09:53 AM
#128
Le Mans Master
Got my RPM from RockAuto...installed myself....done!
08-16-2017, 11:31 AM
#129
Warranty item
Don't understand DIY. Flutter noise in my 2015 Z was increasing (7,300 miles now). Took it in (Elco Chevy/St. louis, Bill the mechanic), mentioned the bulletin, and a short time later had the 'green' belt installed under warranty. Flutter noise completely gone, which is better than when new, as it originally had a very slight hiccup between 4 and 8 cyl. modes.
08-16-2017, 12:13 PM
#130
Le Mans Master
Don't understand DIY. Flutter noise in my 2015 Z was increasing (7,300 miles now). Took it in (Elco Chevy/St. louis, Bill the mechanic), mentioned the bulletin, and a short time later had the 'green' belt installed under warranty. Flutter noise completely gone, which is better than when new, as it originally had a very slight hiccup between 4 and 8 cyl. modes.
1. Wanted the Black RPM belt not the green belt in the tech bulletin;
2. Prefer to DIY rather than the dealer on simple items, ie oil changes that I also do myself.
3. Often must leave the car and come back later...too much time for a simple fix.
4. Already changed the belt tensioner on my dime, so knew how to do it...easy.
08-16-2017, 12:16 PM
#131
Makes sense.
1. Wanted the Black RPM belt not the green belt in the tech bulletin;
2. Prefer to DIY rather than the dealer on simple items, ie oil changes that I also do myself.
3. Often must leave the car and come back later...too much time for a simple fix.
4. Already changed the belt tensioner on my dime, so knew how to do it...easy.
2. Prefer to DIY rather than the dealer on simple items, ie oil changes that I also do myself.
3. Often must leave the car and come back later...too much time for a simple fix.
4. Already changed the belt tensioner on my dime, so knew how to do it...easy.
08-20-2017, 01:38 AM
#132
Melting Slicks
I was trying to duplicate this problem on highway, wasn't able to hear it. Does it happen in certain mph or something?
I have manual transmission, does it happen to A7 as well?
edit: oops I meant M7
I have manual transmission, does it happen to A7 as well?
edit: oops I meant M7
Last edited by okaythen; 08-20-2017 at 01:02 PM.
08-20-2017, 09:38 AM
#133
Le Mans Master
Unless you are in Eco mode with the manual M7, the DOD/AFM will not happen. A8 auto transmission does it in all modes (not while in M).
02-26-2018, 07:19 PM
#135
Melting Slicks
Before I didn't hear anything, but now car got 3k miles and there is some noise during V4 (not very sure if it's similar to the videos), and it disappears as soon as it goes to V8, and comes back when it's V4 again and repeat. There shouldn't be any noise at V4 right? Sounds like mine is leaking?
Last edited by okaythen; 02-26-2018 at 07:23 PM.
02-27-2018, 09:56 AM
#136
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,096
Received 8,929 Likes
on
5,333 Posts
Before I didn't hear anything, but now car got 3k miles and there is some noise during V4 (not very sure if it's similar to the videos), and it disappears as soon as it goes to V8, and comes back when it's V4 again and repeat. There shouldn't be any noise at V4 right? Sounds like mine is leaking?
If you are on the highway cruising at highway speeds the TCC should be locked up and the drive train is direct drive just like it would be with a manual transmission and clutch. I suspect if you are hearing some noise while the car is in V4 mode while cruising on the highway there is some issue causing the noise.
Bill
The following users liked this post:
okaythen (02-27-2018)
02-27-2018, 01:31 PM
#137
Safety Car
02-27-2018, 01:43 PM
#138
Safety Car
Last edited by C7/Z06 Man; 02-27-2018 at 01:50 PM.
04-03-2018, 01:59 PM
#139
Le Mans Master
You have to listen fairly carefully with the sound turned up, but in all three videos the growling sound it makes right before switching back to V8 mode is definitely noticeable. Please let me know if this is the same thing that other people have been experiencing.
