: Supercharger coupler rattle, what will happen long term if not replaced?

10-25-11, 06:12 PM
Dealer isn't going to fix this and i planned on doing this myself down the road maybe in the spring or summer.

Just wondering can this plastic spring coupler snap and cause the supercharger to lock up and fail? What is the worst case scenario for this issue?
Am I loosing boost because of this?

10-25-11, 06:28 PM
The TSB doesn't call for "fixing" it.

10-25-11, 07:05 PM
Just wondering can this plastic spring coupler snap and cause the supercharger to lock up and fail? What is the worst case scenario for this issue?
Am I loosing boost because of this?
Sounds like it is time to roll out this post again:

10-25-11, 07:41 PM
Thanks for posting up that link. It kinda reminds me of how Jaguar handled this same issue 10+ years ago for me. I later found out that you can not purchase ANYWHERE a new Spring Loaded Coupler every single rebuilder or source said that was the case unless Eaton magnasson did the full rebuild. The Jaguar coupler spring eventually snapped once i hit 40k miles.

So in this case maybe that is why dealers are not wasting time to change out these parts or something.

I also wouldn't expect a dealer to install a solid coupler as a TSB but it would be nice to get something addressed so the knocking goes away, its very annoying

So what have most of you guys done here regarding this knock? Leave it alone or go solid?

I havent heard much on how a solid makes more noise but on my older Jaguar that used an old design blower M112 it did make more gear noise from where the rotor packs spun. I do not think the TVS will do that by the nature of its design.

Gary Wells
10-25-11, 08:40 PM
From what I remember of other threads and posts about this subject:
A dealer is not allowed to even go inside the blower for any reason. These are bought in house by GM as completed units and even GM does not tear into them. In the event of a failure of the blower or where it has been documented by a GM dealer that the noise produced by the coupler exceeds that which is allowed by GM / Eaton / Magnusson, dealer is to remove the supercharger and send it to GM, who in turn sends it to Eaton for investigation. There have been about 6 or 7 members that I know of who have documented that their blower was replaced under warranty. The solid coupler if fitted and matched correctly makes no detectable noise.
I think that most have replaced or had replaced the factory coupler with a solid one. Some aftermarket performance shops automatically install the solid coupler as part of their upgrade.
Mine was replaced by D3 when I had about 1200 miles on the car. Cost was about $200 for everything, I think. They did a great job & explained everything as they went along.

10-26-11, 02:34 PM
I have recently replaced the pulley on my V and I had a look a the shaft in the snout.
After 13K miles the shaft had only slight scuffing marks on it.
Have look at the w4me installation video that shows also example of the shaft wearing out:

I had no rattle at all up to now.

10-26-11, 03:20 PM
I have over 100K miles on my 09 V and have had no issues with the stock setup.

10-26-11, 03:35 PM
I have over 100K miles on my 09 V and have had no issues with the stock setup.

Did the rattle noise remain somewhat consistent over the 100K miles or did you notice it get audibly louder ?

10-26-11, 04:52 PM
I have over 100K miles on my 09 V and have had no issues with the stock setup.

You noticed no rattle at all?

10-26-11, 05:38 PM
mine sounds like crap and its so inconsistant of a rattle like the rattle misfires every other cylinder its def the blower coupler

Gary Wells
10-26-11, 06:17 PM
This issue does not happen to all cars. Probably a very small % of them.

10-26-11, 06:22 PM
How come only a small %? What's different on the others?

10-26-11, 07:55 PM
How come only a small %? What's different on the others?

It's called quality control. You get some part out or in by too much and it causes the problem. If the outer and inner tolerances on differnt parts match up you have a problem. Tighter tolerances mean higher manufacturing costs and it's probably cheaper to replace the small number that this happens to than to upgrade the machine tools.

Gary Wells
10-27-11, 08:43 AM
I don't know what the differences between ones that rattle and ones that don't rattle are. Probably in the matching of one to the other and the clearances. Same as the wheel clicking, only a small % are actually affected by this issue. Refer to the engineering response on post # 3 for more details.

10-27-11, 08:55 AM
PIP4523C still instructs technicians to replace the entire blower assembly for a marble type rattle noise at idle... Why isnt your dealer covering it?

#PIP4523C: Marble Type rattle Noise At Idle From The Supercharger - Potential Noise Characteristic - (Jan 26, 2011)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.


A supercharger noise may be experienced at idle that sounds like marbles rolling around in the supercharger. Some may also describe this as an erratic rattle-type noise that sounds similar to combustion noise on a diesel engine.

This noise will only be heard at idle and it will go away when the RPM is raised off of idle slightly. Typically, the hood will have to be open to hear the noise outside of the vehicle or the vehicle will have to be parked next to a wall (ie...restaurant drive-thru, etc) to hear it from inside the passenger compartment.

When comparing this noise to other vehicles, it may be noted that other vehicles exhibit the same noise at idle but some are louder/quieter than others.

This noise may be mistaken for a bad supercharger bearing, which may lead to unnecessary supercharger replacement, but it is most likely a normal noise characteristic of the torsional isolator at idle.


If the noise above is experienced, perform the diagnostic steps below:

1. Park in an open area with the hood and windows closed.

2. With the engine at operating temperature, raise the RPM to 1200 RPM and re-evaluate the noise while sitting inside of the vehicle.

If the noise is no longer present, this should be considered a normal noise characteristic of the supercharger - do not replace the supercharger in an attempt to repair this noise.

If the noise is still present, allow the engine to cool, temporarily remove the supercharger belt, and listen to the noise again. If the noise was present at 1200 RPM with the belt on but is gone with the supercharger belt removed, replace the supercharger by following SI procedures and re-evaluate the concern.Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

10-27-11, 12:11 PM
My coupe has the rattle. I would think that I should get on record with my dealer just in case I end up having to replace the S/C. Got my car last August and it has almost 10,000 miles.

Any thoughts?

Gary Wells
10-27-11, 01:05 PM
I would as a minimum get it documented at your dealers, but I would say that chances are small of S/C replacement.