: "Rattle" at engine shut off??



LFTW8S
10-01-10, 03:10 PM
When I park the V and switch the ignition off...I hear a rattle as the engine finally shuts down. Anyone know what this is? Thanks!

CTSVeee
10-01-10, 03:13 PM
I belive this is from the isolator and according to the dealer it is 'normal'. Some have had the isolator replaced under warranty. I just live with it.

PhxTriode
10-01-10, 04:07 PM
With an aftermarket isolator it went completely away. Not only that but you can actually hear the rotors whining at idle (with a 9.5" pulley)

Gary Wells
10-01-10, 04:30 PM
I belive this is from the isolator and according to the dealer it is 'normal'. Some have had the isolator replaced under warranty. I just live with it.

I am of the opinion that only a couple (3) of people have had the isolator replaced under warranty. Most have been refused, claiming that the noise, up to a certain decibel reading, is normal. Most, or almost all of the isolators have been replaced without s/c replacement have been replaced at owners cost. The s/c isolator is a non-serviceable item and requires s/c replaced if replaced by GM.

LFTW8S
10-01-10, 05:00 PM
I am of the opinion that only a couple (3) of people have had the isolator replaced under warranty. Most have been refused, claiming that the noise, up to a certain decibel reading, is normal. Most, or almost all of the isolators have been replaced without s/c replacement have been replaced at owners cost. The s/c isolator is a non-serviceable item and requires s/c replaced if replaced by GM.

Sounds like something GM would do. So...if they replace the entire S/C...does it include the same type isolator and thus having the same rattle. BTW...what exactly is the isolator's function?

GMX322V S/C
10-01-10, 05:24 PM
It's supposed to isolate/absorb/smooth out the firing pulses at lower RPMs from the supercharger gear drive, so that it didn't cause chatter/backlash noise. Pfft. Instead it introduces a rattle noise of its own. The solid "isolator" really doesn't isolate anything at all--it replaces the spring-loaded isolator with a basically solid coupling.

PhxTriode
10-01-10, 05:59 PM
Gary is correct, there is no part# for the isolator. Only the S/C. What is worse is that Eaton has not changed the design

Gary Wells
10-01-10, 06:55 PM
Lingenfelter solid s/c isolator, I believe about $75.00 or so, from almost any of the forum tune shops.

cbloveday
10-01-10, 07:27 PM
About 4:40 into this video by wait4meperformance you will see what the isolator is. He also shows what the replacement solid isolator looks like.

http://www.youtube.com/watch?v=sm4Jh_B2r6Y

LFTW8S
10-01-10, 09:34 PM
About 4:40 into this video by wait4meperformance you will see what the isolator is. He also shows what the replacement solid isolator looks like.

http://www.youtube.com/watch?v=sm4Jh_B2r6Y

Cbloveday...thanks for the vid. I can't believe the "grove" that the isolator spring caused in the shaft after only 2000 miles. How does GM think that shaft is going to last 100,000 miles without failing?

GMX322V S/C
10-01-10, 09:57 PM
One school of thought is it's kind of like piston rings seating: there's an initial amount of wear and then it slows down dramatically. The rattle is like when piston rings chatter--it never really gets better and often gets worse.

Gary Wells
10-01-10, 11:15 PM
Cbloveday...thanks for the vid. I can't believe the "grove" that the isolator spring caused in the shaft after only 2000 miles. How does GM think that shaft is going to last 100,000 miles without failing?

I don't believe that the groove in the shaft was caused from the isolator spring, although that is the general consensus of opinion. And GM knows that the shaft will last 100K miles because there in nothing attached to the other end of the shaft. Although not a good positive indicator, if the shaft does break off, it should not have catastrophic consequences.
Just IMHO and FWIW though, don't take my word for it. However, when it goes bad, it sounds terrible to say the least.

JFJr
10-02-10, 08:59 AM
I can remember hearing a very brief "rattle" when shutting down the naturally-aspirated LS6 in my 2005 CTS-V, but no noise from my LSA, so WTF?

Jud

Gary Wells
10-02-10, 12:14 PM
I can remember hearing a very brief "rattle" when shutting down the naturally-aspirated LS6 in my 2005 CTS-V, but no noise from my LSA, so WTF?
Jud


I can remember hearing a very brief "rattle" when shutting down the naturally-aspirated LS6 in my 2005 CTS-V...........

That would have had to be detonation, or something other than a s/c isolator noise / issue.


.......... but no noise from my LSA, so WTF? Jud

Only a handful or small % of these cars have the isolator noise / issue.

Read more at http://www.cadillacforums.com/forums/newreply.php?do=newreply&p=2378421&kcplink=1

getbit
10-02-10, 06:20 PM
My 2011 V-Coupe just started rattling with about 2500 miles...as well as the wheel clicking issue and numerous other "noises" and having a couple of items just falling off.

Gary Wells
10-02-10, 07:23 PM
My 2011 V-Coupe just started rattling with about 2500 miles...as well as the wheel clicking issue and numerous other "noises" and having a couple of items just falling off.

My '09 CTS-V S/C isolator went out at 1230 miles. Had it replaced with the Lingenfelter solid isolator by D3 at a cost of about $235 or so, including part, shipping, labor, & tax. Never had any more issues with the s/c isolator since then.

getbit
10-02-10, 09:41 PM
My '09 CTS-V S/C isolator went out at 1230 miles. Had it replaced with the Lingenfelter solid isolator by D3 at a cost of about $235 or so, including part, shipping, labor, & tax. Never had any more issues with the s/c isolator since then.

I'll probably deal with it when I start some of the mods.
Thanks.

Gary Wells
10-02-10, 10:00 PM
A little preventative maintenance never hurt, especially on these cars. If you happen to have the snout polished or the upper pulley changed it probably would be worth the additional cost of doing it.

Titaniumseeker
10-02-10, 11:43 PM
I've had the same rattle sounds at engine cutoff. Took it to the dealer who identified the noise as the isolator but presented me with a document from GM stating that the sounds under a certain decibel was considered normal. However, now at 11K miles, I do not have the rattle at all. Good sign? We will see. Your guess is as good as mine. I am thinking of getting the snout polished and have an isolator ready to replace the stock one.

PremierJosh
10-03-10, 12:16 AM
My 09 was bone stock a driven pretty easy when I bought it at 8100 miles. The mpg average was 17.2 to show you how easy it was driven. When I changed the upper pulley and isolator with in the first week the shaft had pretty deep wear on it so I'm sure all V's isolators are wearing a great deal. I would suggest every owner swap out there isolator to a solid one.

4gear70
10-03-10, 08:57 PM
My 09 was bone stock a driven pretty easy when I bought it at 8100 miles. The mpg average was 17.2 to show you how easy it was driven. When I changed the upper pulley and isolator with in the first week the shaft had pretty deep wear on it so I'm sure all V's isolators are wearing a great deal. I would suggest every owner swap out there isolator to a solid one.

If you looked at the function and how far the spring cannot move off the center axis, you'd realize that it cannot wear the shaft right through.
I think more of a concern should be the cylinders/bearings etc. on cold starts without the use of a block/oil heater or not having your car in a heated garage...

getbit
10-03-10, 11:33 PM
Attn: Hulksdaddy

Hey, Dave.
I cannot respond to your PM as the website is telling me I am too new to use the private message system until I contribute "more"... and I could be spamming.
PM me your email address and I will email you my response.

So, I can receive them but not respond...
Ridiculous.

PSRmark
10-04-10, 12:59 AM
To anyone that is considering swapping to the solid isolater...make sure whoever installs it knows what they are doing. There have been some tolerance issues on some of the isolaters, and in some cases it's way too tight and ends up pushing the rotor pack rearward during install, which is bad because that can cause damage. Some isolaters have been way to loose, and end up sloppier and noisier than a stock unit.

just an FYI take it for what you will...

Offshore78
04-07-11, 12:49 AM
Does anyone have this issue on a 2005 LS6 CTS V S/C. I have a noise only when I shut mine down. Just curious if there is a fix for this?

Jbauer47
04-07-11, 01:55 AM
My entire supercharger was replaced at 300 miles. Two days after I got it back the rattle developed again. I don't think I will be taking it back to the dealer. I also have the wheel click. I am 50/50 right now to live with the noises or get that ISF which would not be fun - but no rattles....