[XQZMYZ]

I have a brand new 2021 ZL1, and every time it starts I get squeaky belts/pulley sounds for the first 30 seconds or so. Is this a known issue? Is there anything I can do to get rid of this? I searched the forums and I did not see any mention of this. Thanks.

[FrostZ]

I had a very similar thing occur when I bought my car in 2019. I had less that 2k miles and I heard a very light squeak from the front drive. I used a bearing stethoscope I had on hand along with the old screw driver to the ear trick to narrow it down to an idler pulley for the supercharger belt. I brought it back to the dealer under warranty and it was in fact that pulley which they replaced for no charge of course. Sometimes you just get a defective part here and there unfortunately. I’d think the same is the case for you if you can confirm it’s from the front drive.

[XQZMYZ]

Originally Posted by FrostZ

I had a very similar thing occur when I bought my car in 2019. I had less that 2k miles and I heard a very light squeak from the front drive. I used a bearing stethoscope I had on hand along with the old screw driver to the ear trick to narrow it down to an idler pulley for the supercharger belt. I brought it back to the dealer under warranty and it was in fact that pulley which they replaced for no charge of course. Sometimes you just get a defective part here and there unfortunately. I’d think the same is the case for you if you can confirm it’s from the front drive.

This is more of a squeaky pulley sound for about 15-20 seconds or so during initial startup, goes away after the kickdown. Maybe I'll swing by the dealer and see what they say. Thanks for the info.

[hawk02]

Originally Posted by XQZMYZ

This is more of a squeaky pulley sound for about 15-20 seconds or so during initial startup, goes away after the kickdown. Maybe I'll swing by the dealer and see what they say. Thanks for the info.

Closely monitor the squeal. It will likely migrate to a full blown bad bearing at some point.

My ‘17 ZL1 squealed for 15-30 seconds on cold startup during the first year of ownership. I posted a YouTube video on here to see if the engines of other Zl1 owners made the same noise when their cars started up. The consensus was no. I’ll see if I can find video so you can compare it to yours. Midway through the second year of ownership, the bearing on the supercharger idler pulley started squealing all the time. The pulley was replaced under warranty. The new pulley has been squeal-free.

Good luck. The dealer may not be able to diagnose unless you leave the car for a few days in order for them do a cold startup.

Here’s a photo showing the pulley that was bad on my car.

[hawk02]

Here’s the video I posted of the noise on cold startup.

https://youtu.be/1aAEydsE_D8

[jaybee924]

I'm no expert but that don't sound right at all.

[hawk02]

Originally Posted by jaybee924

I'm no expert but that don't sound right at all.

I didn’t think so either. I had one other ZL1 owner tell his engine did the same thing.

As you can hear, the noise starts to dissipate as the engine idle starts to go down. It did this for about a year and half until the bearing finally crapped. When that happened the squealing noise was constant and a lot louder. I used a long wooden dowel to diagnose which pulley was bad. You could hear it buzz and vibrate like a nest of angry bees.

[Camaro1973]

Originally Posted by hawk02

Here’s the video I posted of the noise on cold startup.

https://youtu.be/1aAEydsE_D8

This here is a very easy to diagnose bad bearing on a pulley. I've heard many others, and alot of times its very hard to tell. This here though is very easy as you can hear the grinding/vibrating stopping and starting which is a clear giveaway.


If the OP's sounds like this replace it now before it falls apart

[FrostZ]

Sounds just like a louder version of my pulley which was also an idler for the supercharger. In my case it was directly below the snout of the blower but I agree with everyone that you should definitely get it checked out.