: Whats this rattle on shutdown?

06-19-11, 01:35 PM
Sometimes when I shut the engine down I get this rattle right as it shuts down. It's pretty loud almost like something is loose and shaking around. I've read about the iso rattle and I have heard that on mine from time to tome at idle. Is this rattle coming from the same thing? Anyone have similiar issue?

06-19-11, 02:04 PM
You might have a poor grade of fuel or somehow your timing got messed up. The engine isn't shuting down properly. Can't think of anything else. Cecil...............

06-19-11, 02:47 PM
93 octane, no engine codes, only does it sometimes?

06-19-11, 09:32 PM
Mine does it, too. Definitely a supercharger noise which I attribute to just the tolerances in the rotors making some noise when the engine goes without spark to shut down. IIRC, the isolator noise presents itself under idle speed conditions....which I also hear. So far, I've not been terribly concerned about it. You are not alone.

06-19-11, 10:19 PM
Thanks Trapspeed, I was getting a little worried. Anyone else?

06-19-11, 10:39 PM
Are you guys sure that you're not hearing the infamous isolator rattle coming from the blowers input shaft? I hear mine during idle mostly, but very little to no noise during shutdown ..


06-19-11, 11:57 PM
That marble sound you are hearing is the isolator. GM states the sound is normal. There are pleanty of threads on this issue, The sound drove me crazy especially sitting at idle so I swapped in a isolid isolator. Note: Taking this action will most likely void your SC warranty.

06-20-11, 08:34 AM
I've heard that sound a few times on shut down. Don't think it is the isolator, which I hear at idle... but doesn't bother me.

If you are a previous V1 owner, you'll recognize the sound. It sounds the same as when you'd shut down the LS6.
That sound was determined to be from the fluid filled motor mounts, when they started to leak. I have no idea if the V2 has a similar design mount. I hope not.

Mine is not consistently making the noise on every shut down, so I'm sort of just 'listening' for now.

06-20-11, 08:58 AM
ya...reminds me of my V1 Motor mounts also.....Once replaced with Mounts from lindsay cadillac...that rattle went away....but....put a LOT of vibration into the drivers seat, steering wheel, and Shifter :( ....( Got better as engine heated up )

Good luck

06-20-11, 09:44 AM
cannot duplicate.