: Been hearing a mild rattle coming from engine under the hood, can anyone comment?



MrMaschine
09-28-11, 12:29 AM
I have brought this up 5 times to dealers and they all say this noise is normal which i think is BS.

I had an almost identical issue back in 2001 with a Jaguar XJR when the blower bearings failed from the pulley kit i installed. I know on the old Jaguars there was a plastic spring clutch type coupler that engaged the snout to the blower vanes. over time those springs would break and also cause a rattle.

Is this what the issue is on the CTSV? Is there any TSB that i can somehow force my dealer to do a repair?

I was considering the Lingelfelter pulley kit which seems to include a solid Delrin coupler. but am now worried it will cause something to fail

Let me know what I should do, car runs fine just noisy and its worse when i turn the engine off.

MReiland
09-28-11, 06:29 AM
There is a spring loaded isolator between the snout pulley and blower. The TSB lists the sound as 'Mables in a can' sound. Does this sound like what you are talking about.

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

smackdownCTSV
09-28-11, 10:05 AM
Special delivery!

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

Subject: Marble Type Rattle Noise at Idle from the Supercharger - Potential Noise Characteristic Subject: Marble Type Rattle Noise at Idle from the Supercharger - Potential Noise Characteristic


Models: 2009-2011 Cadillac CTS-V Models: 2009-2011 Cadillac CTS-V

2009-2011 Chevrolet ZR1 Corvette 2009-2011 Chevrolet ZR1 Corvette

with 6.2L Supercharged Engine (RPO LS9 or LSA) with 6.2L Supercharged Engine (RPO LS9 or LSA)

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This PI was superseded to update model years. Please discard PIP4523B. This PI was superseded to update model years. Please discard PIP4523B.


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

Condition/Concern: Condition / Concern:
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. 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. 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. 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. 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.

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

•Park in an open area with the hood and windows closed. • Park in an open area with the hood and windows closed.
•With the engine at operating temperature, raise the RPM to 1200 RPM and re-evaluate the noise while sitting inside of the vehicle. • 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 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. 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. 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.

MrMaschine
09-28-11, 10:18 AM
Yes this is exactly what it appears to be.

What I want to know is the following:

1. is the coupler broken or anything broken causing this?
2. Why is the supercharger replaced under this TSB? What is the primary cause?
3. Will installing a solid coupler solve this problem?
4. Am I loosing boost because of this?

How can I get the dealer to even move forward on this. They just seem to always avoid anything that requires real labor intensive work and paperwork which drives me mad.

smackdownCTSV
09-28-11, 06:49 PM
The dealer will do it, if not, go to another one. Even a Chevy dealer. They just do the isolator unless it's really bad, but considering you have a 2011, it shouldn't be. You're slowing wearing the shaft. There are pics on here and youtube. Not sure about boost, but you probably have some false knock.

MrMaschine
09-28-11, 09:06 PM
So if i get this solid coupler can I install this myself and call it a day or there is more to it than that?

These dealers suck in the Tri State because I have a D3 suspension and stuff they balk about the warranty etc.

I honestly rather fix this on my own just because of the hassle making appointments, leaving the car there for days and they then
tell me its normal, i already went this route multiple times and its a waste of time for me.

Tedboss1
09-29-11, 11:08 AM
Have look at the wait4me video he explains the isolator problem:
http://www.youtube.com/watch?v=sm4Jh_B2r6Y

MrMaschine
09-29-11, 12:08 PM
Hey thanks for posting that waitforme video it really explains a lot.

the coupler is identical to the ones Jaguar used 10 years ago with the same spring chatter.

I cant believe the wear on the snout shaft. What now worries me is my car has about 20k miles and I am afraid to even look.

Does the dealer even care to replace that portion under the TSB? Going with the solid coupler and having a worn shaft does that pose an issue?

Delta
09-29-11, 12:10 PM
i would take it in, get a brand spankin new supercharger, then put the Ligenfelter stuff on. Why not get a free $2,000 blower?

Tedboss1
09-29-11, 03:04 PM
Going with the solid coupler and having a worn shaft does that pose an issue
No it should not be a problem as the solid isolator is not even touching the shaft. It rests and transmits a power through the 3 pins shown in the video.

smackdownCTSV
09-29-11, 03:22 PM
i would take it in, get a brand spankin new supercharger, then put the Ligenfelter stuff on. Why not get a free $2,000 blower?

It doesn't work like that anymore. Cadillac isn't going to be warrantying the whole thing anymore. Just like when they were warrantying the wheels for the wheel click TSB. Not no more!