Well, I got my 2012 ZL1 back this afternoon. It spent two nights INSIDE the Radley Cadillac shop. The first because I brought it in later in the afternoon so all they did was diagnose the problem the first day. The second day they wanted me to hear the new noise on a CTS-V that had a recent supercharger replacement. The owner had brought it back in because of the "new" noise. They put it side by side with my car as a comparison. They are two completely different noises, so I'll be on the lookout for the new noise when it starts to appear sometime down the road. It is in the 800-900RPM range and I can confirm it is like a buzzing noise but quickly goes away at rpms lower or higher. The TSB on this says it is
normal and GM hasn't made any decisions on whether they'll need to do anything about it later. For now, that's the price you'll pay for having the solid isolator.
So after comparing the two cars, they gave
me the choice of replacing the supercharger or not. They had the part in stock and could do it right away. Or I could wait to see if it got any worse and just come back then. (Mine really was not that noticeable at 8,410 miles, but it had just started when I took it out of storage a couple of weeks ago. Who knows how long before it got worse.)
I explained to the Service Manager and the technician that I was holding off doing power mods, headers, pulley and a tune until I had the supercharger replaced because I wanted to make sure the warranty would not be affected. I was told by the Service Manager that a tune and headers would not affect this supercharger replacement <at their dealership> so I was free to replace it now and start the mods, or start modding with the old supercharger. Either way, my ZL1 would be covered under the warranty--as long as the mod wasn't the actual problem.
That was refreshing to hear the service manager say that. I could tell he is a car guy and wanted to put me at ease. He manages the Chevy store and the Cadillac store across the street, so the guy is pretty busy and is responsible for a two large shops. However, not wanting to test his statement, I went ahead and decided to get it replaced.
I got the car back today and so far, so good. I drove it about 75 miles after I picked it up and I really opened it up a couple of times. Everything is tight and right. The car definitely feels better and so far it isn't making the "new" noise.
Anyway, I just wanted to share my experience with the Forum. Nothing new here, really. I'll keep my eye on it for a couple more weeks and then the mods begin.
