04-20-2020, 08:38 PM | #1 |
Drives: Zl1 Join Date: Jul 2017
Location: Dallas
Posts: 7
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Supercharger rattle
So I took it in they did the so call recall on the supercharger but I still hear it a rattle is this normal 2012 zl1
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04-20-2020, 09:41 PM | #2 |
Drives: 2014 ZL1 Join Date: Jun 2009
Location: Tucson, AZ
Posts: 314
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No. If they did the recall IAW the TSB it's a new blower that makes no rattle. However, they will still install another crappy spring coupler will also eventually fail again. Maybe it's a bad coupler right out of the gate?
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04-21-2020, 09:15 AM | #3 |
Drives: ZL1, 2013, tri-coat-red, manual Join Date: Nov 2013
Location: Michigan
Posts: 1,607
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04-21-2020, 02:42 PM | #4 |
Drives: Chevy Camaro ZL-1 Join Date: Feb 2020
Location: Phoenix Arizona
Posts: 62
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I am going in for the third time. Same rattling noise.
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04-21-2020, 04:52 PM | #5 |
Drives: 2013 Triple Black ZL1 Vert M6 ECF Join Date: Mar 2011
Location: Trenton, Michigan
Posts: 7,047
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FWIW, in the original bulletin, in order to determine if the problem was a faulty coupler, it described listening for the rattle at idle.
"CONDITION Some 2009-2013 model year Cadillac CTS and 2012-2013 model year Chevrolet Camaro vehicles, equipped with a 6.2L V8 engine (LSA), may have a condition where the engine’s supercharger may not function as designed. If this were to happen, the supercharger may develop a noticeable rattle noise at idle. The noise will typically go away when the engine RPM is raised slightly above idle. However, if left uncorrected, the problem, over time, may lead to contamination of the lubricating grease and cause the bearing to squeal. If left unaddressed, the bearing may overheat and can cause engine seizure or a no-start condition." Another portion of the bulletin says...... "Note: To improve reliability of the supercharger one of the changes made was to go to a solid coupler between the geartrain and the drive pulley. A tradeoff to this improvement is that manual transmission vehicles may experience a flutter or rattle at low RPM (800-900) and high load (second or third gear). This flutter only lasts a moment and is a normal characteristic of this design." |
04-21-2020, 05:12 PM | #6 | |
Drives: ZL1, 2013, tri-coat-red, manual Join Date: Nov 2013
Location: Michigan
Posts: 1,607
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04-21-2020, 06:53 PM | #7 |
Drives: 2010 Chevrolet Camaro 2SS/RS Join Date: Dec 2015
Location: Massachusetts
Posts: 229
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I did the solid isolator install on my 2012. I get a low rpm “flutter/heat shield” type noise at 800-900rpm. I’m running a stock size upper pulley.
My understanding is many go solid and do a smaller pulley at same time which changes harmonic range so no one notices.
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04-21-2020, 07:10 PM | #8 | |
Drives: ZL1, 2013, tri-coat-red, manual Join Date: Nov 2013
Location: Michigan
Posts: 1,607
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04-22-2020, 12:24 AM | #9 | |
Drives: 2013 Triple Black ZL1 Vert M6 ECF Join Date: Mar 2011
Location: Trenton, Michigan
Posts: 7,047
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Quote:
It's been probably 5 years since they replaced my SC and I've never had a problem with it since. And I don't know about now, but back then when the TSB came out, GM considered the entire SC assembly (including the coupler) as a single replaceable item that was then sent back to the OEM, Eaton. And yes, other than a Rotofab CAI, my engine is bone stock. Last edited by HDRDTD; 04-22-2020 at 12:36 AM. |
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04-22-2020, 05:20 AM | #10 | |
Drives: 2013 ZL1 Camaro Join Date: Feb 2018
Location: Michigan
Posts: 218
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04-22-2020, 09:14 AM | #11 | |
Drives: ZL1, 2013, tri-coat-red, manual Join Date: Nov 2013
Location: Michigan
Posts: 1,607
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Quote:
Not sure I understood the question, but the original Eaton had a spring Isolator. There had been numerous complaints from the Cadillac group of a marble sound at idle but GM ignored the complaints as normal operation. When the Z was introduced with all the focus on a true track car that was fully warranteed and owners started complaining GM took notice, especially when many started replacing the Spring Isolator with a solid pinned unit from Lingenfelter. Eventually GM started the TSB extended warranty coverage and began replacing initially the whole unit with a new Eaton. You couldn’t just do the Z's and not the caddy's for the same problem so caddy was added to the TSB. That in itself consumed all available stock as the caddy problem went back to 2009. So for a little over a year the new units were available for the Z but unless you got them early a massive inventory problem arised and you were waiting. To solve this GM went back to providing a refurb Eaton with a pinned solid, and eventually went back to a supposedly a new and improved Spring Isolator and stopped any further Solids from being installed. I have heard in some cases they will just replace the snout with a spring isolator but since I don't know anyone that has actually had it done I cannot confirm its true. They also refunded anyone who had already paid to have a solid put on and extended their warranty. Not sure I answered your question. |
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04-22-2020, 09:17 AM | #12 |
Account Suspended
Drives: 2012 2SS CAMARO 45th Join Date: Apr 2011
Location: St. Charles, IL
Posts: 18,663
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The isolators gm uses are junk. Get an aftermarket solid isolator and call it a day. If we do a pulley swap it would be no charge to do the isolator as well. We sell solid isolators by Metco for like $60 on our site.
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04-22-2020, 11:49 AM | #13 |
Drives: 2013 Triple Black ZL1 Vert M6 ECF Join Date: Mar 2011
Location: Trenton, Michigan
Posts: 7,047
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First off understand I am NOT an engineer. All the opinions stated here are mine only as an ZL1 owner and in no way reflect official opinions of any of the manufacturers involved.
From what I remember, in the beginning, the coupler that Eaton designed/used, was a spring-loaded coupler that had a spring that encircled the shaft of the coupler and was meant to absorb some of the natural rattle/vibrations the internal SC rotors had at idle when it's drive train was essentially un-loaded. Probably due to the design of the internal gearing, but that's just a guess on my part. This could be heard as a 'rattle' if you will again at idle speeds when the internal drive train was unloaded. As soon as the engine was reved. the internal gearing of the SC was then under load taking up any gear train 'play', and the rattle would diminish. The original coupler was designed to use a spring to help absorb some of that gear train 'slop', and it used a spring wrapped around the central shaft of the coupler. As the spring compressed/extended as it wrapped itself around the couplers shaft, people noticed it would wear spiral grooves into the shaft of the coupler and they saw this as a design flaw. Again from what I remember, Eaton explained that the wearing of the grooves into the shaft was actually a design feature because they intentionally made the material of the shaft just a tad softer than the spring material. The coupler in it's original design was working properly and doing it's job as it was intended. However, people would hear the rattle, and they didn't like it. They saw it as something sounding wrong. When they looked at the shaft of the coupler and saw the grooves the spring had worn into the shaft, it seems their fears were confirmed, something was wrong. This shouldn't be happening, and panic set in. Thus, Eaton decided to replace the spring loaded coupler with a solid one, GM issued the TSB, and the great SC replacement program was under way. Just speculation on my part here, but if Eaton had decided as a result of testing that a spring loaded coupler was desired to help absorb some of the internal gear action, then using a solid coupler was going to negate the absorbing function and that was not an ideal situation in their eyes, so, the again went back to a spring-loaded couple, but this time they packed it with grease to help reduce the wear on the shaft due to the spring wrapping and the grease would also help dampen the rattle sound, and I believe that's where we are these days. Yes many people have decided to replace their couple with a solid one to totally eliminate any wearing of the shaft and are very satisfied with the end result. I have absolutely no problem with them doing so. As stated in an earlier message, My ZL1 is a '13 that was delivered in August of '12, and the local dealer replace the SC sometime in either '13 or '14 I don't remember exactly when because THEY heard the rattle when the car was in for an oil change. My engine is totally stock except for a Rotofab CAI, and at 48k miles now with no problems at all. I can only believe that a major company such as Eaton that has been manufacturing SC for a long time, must have found some reason in their durability testing that made them decide to include a spring-loaded coupler rather than a less expensive simpler solution such as a simple solid coupler. Getting down from my soapbox now, let the comment/flames commence......... |
04-22-2020, 12:22 PM | #14 | |
Drives: ZL1, 2013, tri-coat-red, manual Join Date: Nov 2013
Location: Michigan
Posts: 1,607
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Quote:
Pretty accurate. Was the Spring Isolator designed to absorb inertia of 800 crank HP and beyond. Nope. |
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