Supercharger replacement / Flutter ?

[HDRDTD]

Originally Posted by djnice

Did you leave the CAI on when you took it to the dealer for the SC?

I left my RotoFab on. No questions asked about it.

[CRTZL1]

Originally Posted by djnice

Did you leave the CAI on when you took it to the dealer for the SC?

Mine stayed on as well!

[RLHMARINES]

Originally Posted by djnice

Did you leave the CAI on when you took it to the dealer for the SC?

YES!!

I left my ported throttle body, catch can and C.A.I. on and my service manager and I were in talk about other mods that may come in the future.

[djnice]

Yeah, its pretty obvious the issue has nothing to do with mods.

[Admiral Ballsy]

Originally Posted by Samson2029

Do the new 2014 and 2015 manuals have this rattling with its facory installed upgraded SC??

Yes, they do. My CTS-V (11/13 build) has it, and I've been fighting it ever since. Apparently my dealer is too stupid to find the bulletin that explains it, since I've had to diagnose it on my own. Mechanics are nothing more than appliance repairmen anymore, they're not allowed to actually think.

Originally Posted by Samson2029

Customers should not accept this after paying close to 60 000$ This is an engineering screw up by GM and Eaton. If I were to test drive a 2015 zl1 and have noticed this vibration or rattle related to the solid isolator, it would have been enough for me not to purchase the car.

Add $10K to that, in my case.

I agree, I'd have not bought the car. GT500s prior to 2013 used the TVS1900 and it didn't rattle, it's got to be something either unique to the GM implementation or it's just sloppy QC on Eaton's part. But either way I don't see any way around it, if the former it's pervasive; if the latter, I somehow have to get a new supercharger and hope it's got tighter tolerances.

[jayno20]

So people are saying this "flutter" is caused by the solid coupler? Anyone have a video of this noise?

[Vroom]

Mine quieted down a little so its hard to get a video. I think its worse when the car gets hot so I'll be trying again

[vatechguy3]

Would trying the LPE coupler be worth it?

Tony

[Admiral Ballsy]

Originally Posted by jayno20

So people are saying this "flutter" is caused by the solid coupler? Anyone have a video of this noise?

I don't have anything of the noise in situ, but here's the cause:

Video

If you take the belt off and twist the pulley back-and-forth rapidly, do you get any noise? There's clearance in mine - not much at all, it would be difficult to measure in terms of angular displacement - but the conditions where the rattle occurs seem to create a resonance or oscillation where the rotors are transitioning between being driven and bouncing off the other side of the lash due to inertia. The spring in the original coupler kept 'positive force' on the gear set so this wouldn't happen.

I wonder if all it would take to fix this is for the ECM to command the bypass valve to partially close under these conditions, to put just enough load on the rotors to keep them damped.

[Kevlar382]

Anybody interested in a 2012 ZL1? It has 1700 miles, never driven the rain, and was broken in the way GM said it should be. I did not buy this car to have somebody at my local dealership take my engine apart, but it back together, and then have to explain to anybody who rides in why I have a car that sounds like a piece of $hit.
I have always owned GM cars, right now I have 7 Chevys, but I can't believe how bad they dropped the ball on the ZL1. They didn't do enough testing to this car before they put it on the market and now it's our problem.
GM should take our cars back and get there act together. I'm guessing the new Z06 won't be any better.

[Admiral Ballsy]

Here's what I think happened:

• Eaton builds the original TVS for the CTS-V program with the spring isolator/coupler. It's a good idea, a good design (I found the patent on it, back from '88).
• Some segment of the CTS-V population experiences the marble sound after a while. It's caused by the abrading/compressing of the shaft, to the point that there's a little clearance between it and the spring when the latter 'unloads' at idle. They (rightfully) bitch about this. GM says "it's normal", which it is, but "normal" and "acceptable" are not mutually inclusive.
• Ed somebody from GM says it's by design, explains why they did it the way they did, says there'll be a different noise if they go to a solid, don't worry, nothing bad will happen.
• The ZL1 comes out, with the same setup and the same results.
• For some unknown reason, they switch to a solid in MY 2014 and start a replacement program. And, what do you know, the new noise Ed predicted does indeed show up.

The only reasons I can think of for the switch are that they either got tired of the marble noise complaints, or that they figured out that the worn material can/does get past the bearing seal(s) and causes bearing failure.

I'm guessing the latter.

What do I do about this? Good question. Right now, I see these options:

1. Do nothing (always the simplest option), live with it;
2. Sell the car and move on with something else;
3. Scrounge up a spring coupler, install it, and hope I never have issues with it;
4. Hope something bad happens to the blower while in warranty, and hope the replacement has a tighter tolerance stack in the drive;
5. Hope they eventually come up with an R&R program for this.

I don't think I can do 1. 5 seems so unlikely as to be wishful thinking (they're not making any more of these, 2015 ZL1s and 500 CTS-V coupes excepted). 4 is statistically like winning the lottery.

That leaves 2 and 3. There's nothing else out there I really want, except maybe an M6 SS, but in any case I sure don't want to take a $15K hit.

Therefore, 3 seems like the only reasonably *actionable* way to go. It would technically void the warranty, but since GM doesn't allow dealers to open the thing, I think worst-case is that it would eventually get replaced under the marbles TSB and then I'd be right back where I am now.

So, there's no good choices...

[boondocksaint]

Originally Posted by Kevlar382

Anybody interested in a 2012 ZL1? It has 1700 miles, never driven the rain, and was broken in the way GM said it should be. I did not buy this car to have somebody at my local dealership take my engine apart, but it back together, and then have to explain to anybody who rides in why I have a car that sounds like a piece of $hit.
I have always owned GM cars, right now I have 7 Chevys, but I can't believe how bad they dropped the ball on the ZL1. They didn't do enough testing to this car before they put it on the market and now it's our problem.
GM should take our cars back and get there act together. I'm guessing the new Z06 won't be any better.

That's a bit of a Chicken Little argument and a logical fallacy to boot, regarding the Z06.

As far as the coupler noise is concerned, take the 10k hit you'd normally eat in depreciation, get a better blower and enjoy the car. Or sell the car to prove to GM that you're seriously dissatisfied and have them ignore you, too.

Or, maybe we could ask the aftermarket community to solve the problem. Whatever they do, it'll sell like friggin' hotcakes.

[jayno20]

I'd like to hear what this noise sounds like. I have a '14 and I am hearing something that sounds like its in the drive train. In all honesty though it is something I have heard in every one of the manual cars I have owned if started off in first gear at a low RPM.

Seems more like a "shudder" to me, but I am not sure if this is the same noise you guys are getting.

[Admiral Ballsy]

All T56/TR6060 cars I've driven have some drivetrain rattle. I've owned a '99 Camaro SS, a 2004 Z06, and I currently have a 427 convertible and the CTS-V.

This ain't that, although it does tend to present in the same circumstances. I initially thought it was a heat shield - it sounds EXACTLY like sheet metal rattling against something. After confirming that it in no way could actually BE a heat shield, I assumed it was the guts of the dual-mass flywheel - since that's the only non-common denominator (all my other cars had solid flywheels).

But a guy on LS1tech suggested that I slip the belt and see if it went away. I thought he was crazy, since it's nothing like the supercharger rattle everyone's been on about since 2009.

I was at wit's end, so I tried it. And he was right. And it turns out that GM has been aware of it since at least April, when that PIP was released, but my dealer either wasn't smart enough to look it up or wasn't forthcoming enough to share with me.