: loud intermittent noise, directly on top of engine



Jdani
07-07-13, 01:41 PM
Hello, i have a 2012 cts v sedan auto with 18k miles. I hear this loud noise it comes and goes but lately its been more frequent. last time it was making noise i pulled over and opened hood and sounds like its directly on top of the engine. Any thoughts on this and has anybody ever experienced this.
when i brought it to the dealer of course it went away on the way there and they couldnt find it.

spearfish25
07-07-13, 03:20 PM
You've given absolutely no description of the noise aside from being 'loud' and 'on top of the engine'. It's like going to a doctor and only saying your body hurts sometimes. Without describing it better or providing a video clip, no one is going to be able to help.

GMX322V S/C
07-07-13, 04:08 PM
Hello, i have a 2012 cts v sedan auto with 18k miles. I hear this loud noise it comes and goes but lately its been more frequent. last time it was making noise i pulled over and opened hood and sounds like its directly on top of the engine. Any thoughts on this and has anybody ever experienced this.
when i brought it to the dealer of course it went away on the way there and they couldnt find it.
Does it sound like a small block of wood or a rock rattling around inside a coffee can? If yes, you probably have the dreaded "isolator rattle." Lots of controversy has surrounded this issue from almost day one. We have been assured by the CTS-V program manager himself (search for posts by Ed Piatek on this site) that the system is operating "as designed," however, there are several reported cases of dealers replacing the entire supercharger assembly under warranty as a customer satisfaction measure (the only factory-approved method for addressing the issue, which incidentally can lead to issues on its own if the repairing tech is a doofus).

At the risk of voiding your supercharger warranty, you can have a 3rd-party replace the factory isolator with a solid coupling (I've been in this camp for over 4 years now). The solid coupling should eliminate the rattling noise, but ostensibly can introduce, according to Mr. Piatek, the noise the isolator was designed to prevent, a so-called supercharger gear drive backlash noise. I don't really know what this sounds like, but perhaps others can chime in if they've experienced it.

Jdani
07-07-13, 04:56 PM
You've given absolutely no description of the noise aside from being 'loud' and 'on top of the engine'. It's like going to a doctor and only saying your body hurts sometimes. Without describing it better or providing a video clip, no one is going to be able to help.

Sounds like a bad Ac compressor would or a very bad belt night sound. It's a loud whining sound

bbradyc5
07-07-13, 04:59 PM
Could be a bad SC snout bearing....just take a piece of hose and put it to various spots on the engine and your ear to try and pinpoint where it's coming from.

Jdani
07-07-13, 05:07 PM
You've given absolutely no description of the noise aside from being 'loud' and 'on top of the engine'. It's like going to a doctor and only saying your body hurts sometimes. Without describing it better or providing a video clip, no one is going to be able to help.

Plus it has to so with rpms so like if you rev it a bit it might go away or vice versa. But sometimes it's steady. The one thing though it doesn't get louder as you rev it. Hope this makes sense

spearfish25
07-07-13, 06:25 PM
Sounds like you just have to hit the dealer when the sound is happening. The rattle of the sc is the only other thing I could think of that would be relatively normal. But that wouldn't be something that makes you stop driving to investigate.

Jdani
07-07-13, 09:33 PM
Thanks guys I agree I have to hit dealer when it's making noise.

Cadillac Cust Svc
07-08-13, 10:48 AM
Hello, i have a 2012 cts v sedan auto with 18k miles. I hear this loud noise it comes and goes but lately its been more frequent. last time it was making noise i pulled over and opened hood and sounds like its directly on top of the engine. Any thoughts on this and has anybody ever experienced this.
when i brought it to the dealer of course it went away on the way there and they couldnt find it.

Hello Jdani,

I see you have been offered great advice from the community. I am sorry to hear you are experiencing an intermittent noise with your vehicle. I understand how this can be frustrating when an issue is intermittent and unable to duplicate while at the dealer. I recommend making note of the conditions the vehicle is under the next time this noise occurs. Unfortunately, at this point, the best thing is to take it to the dealership when the noise returns because they are certified technicians who will be able to further help with the vehicle concern. If there are any other questions or concerns you would like to discuss, we can be reached via private message.

Sincerely,

Laura M.
Cadillac Customer Care