Chirp Chirp Chirp - Does your ZR1 also sound like this?
04-06-2019, 07:08 PM
#1
Drifting
Thread Starter
Chirp Chirp Chirp - Does your ZR1 also sound like this?
More of my issues. Car makes this chirp chirp chirp annoying noise for about good 10 minutes when cold. Then this noise goes away.
04-06-2019, 08:44 PM
#3
Drifting
Thread Starter
I have also another issue where if I do multiple runs close to WOT (not very aggressive) pulls followed by quick stop and idle stationary, white smoke starts coming out of the supercharger/scoop area on the hood.
04-06-2019, 09:02 PM
#4
More of my issues. Car makes this chirp chirp chirp annoying noise for about good 10 minutes when cold. Then this noise goes away.
https://youtu.be/weOqMIO5evA
https://youtu.be/ZR5tWIn6qSQ
https://youtu.be/weOqMIO5evA
https://youtu.be/ZR5tWIn6qSQ
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dee zed (04-06-2019)
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04-06-2019, 09:43 PM
#7
Drifting
Thread Starter
04-06-2019, 10:34 PM
#8
04-08-2019, 08:40 AM
#9
I think your chirp noise is the injectors at idle, they are just loud. Many cars these days have “clicky or chirpy” injectors...my car makes the same noise, we used to associate this noise as ticking rockers but it’s just the injectors! You’re fine, floor it...
Last edited by SilveradoSS500; 04-08-2019 at 08:28 PM.
04-08-2019, 09:30 AM
#10
Instructor
I think your chirp noise is the injectors at idle, they are just loud. Many cars these days have “clicky or chirpy” injectors at idle... my car makes the same noise, we used to associate this noise as ticking rockers but it’s just the injectors! You’re fine, floor it...
Mine chirps as well.
08-01-2019, 03:10 PM
#11
Instructor
Member Since: Aug 2004
Location: Kansas City Missouri
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Chirping Noise
My 2010 is doing this as well. I never noticed it until about a month ago because I never let it just sit and idle a bunch after cold starting, but last month I did and when I heard this noise I was like wth. Mine only does it at idle on warm up, but anything off idle you don't hear it anymore. Once you drive it the sound goes away once you are back at idle again and I never hear it again until the next time I get in the car from being completely cold. I saw this GM bulletin about it on the page and then ran into your post in the process.
#PIP4734: Brief Chirp / Squeak Noise On Cold Start - Possible Noise Characteristic - keywords BQMI - (Nov 5, 2009)
Subject: Brief Chirp/Squeak Noise on Cold Start - Possible Noise Characteristic
Models: 2009-2010 Cadillac CTS-V
2009-2010 Chevrolet ZR1 Corvette
with 6.2L Supercharged Engine
(RPOs LS9 or LSA)
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may complain of a brief chirp/squeak noise on cold start that sounds like an accessory belt noise.
The noise may last as long as two minutes but may be much shorter when warmer ambient/coolant temperatures are present. Once the vehicle is warmed up, it may not occur again until the next cold start.
Upon inspection, the technician should be able to isolate the noise to the top, rear of the engine and may mistake it for a supercharger, exhaust, or belt noise.
Recommendation/Instructions:
If this exact noise is encountered, it should be considered a normal noise characteristic and no repairs should be attempted.
This noise is radiated off of the exhaust system during cold start operation as spark timing is retarded to help warm up the catalytic converters
#PIP4734: Brief Chirp / Squeak Noise On Cold Start - Possible Noise Characteristic - keywords BQMI - (Nov 5, 2009)
Subject: Brief Chirp/Squeak Noise on Cold Start - Possible Noise Characteristic
Models: 2009-2010 Cadillac CTS-V
2009-2010 Chevrolet ZR1 Corvette
with 6.2L Supercharged Engine
(RPOs LS9 or LSA)
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may complain of a brief chirp/squeak noise on cold start that sounds like an accessory belt noise.
The noise may last as long as two minutes but may be much shorter when warmer ambient/coolant temperatures are present. Once the vehicle is warmed up, it may not occur again until the next cold start.
Upon inspection, the technician should be able to isolate the noise to the top, rear of the engine and may mistake it for a supercharger, exhaust, or belt noise.
Recommendation/Instructions:
If this exact noise is encountered, it should be considered a normal noise characteristic and no repairs should be attempted.
This noise is radiated off of the exhaust system during cold start operation as spark timing is retarded to help warm up the catalytic converters
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2019 ZR1 (08-01-2019)
08-01-2019, 08:26 PM
#14
Racer
Mine chirps also.
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duanesZ06 (08-04-2019)
08-01-2019, 11:43 PM
#16
Pro Mechanic
Pro Mechanic
(snip)
If this exact noise is encountered, it should be considered a normal noise characteristic and no repairs should be attempted.
This noise is radiated off of the exhaust system during cold start operation as spark timing is retarded to help warm up the catalytic converters
If this exact noise is encountered, it should be considered a normal noise characteristic and no repairs should be attempted.
This noise is radiated off of the exhaust system during cold start operation as spark timing is retarded to help warm up the catalytic converters
A month or so ago, I got so curious about it, I rolled the car into the shop, got it up on stands, fired the motor then grabbed my stethoscope and rolled under the car on my spiffy new GearWrench creeper.
I found the chirping noise was coming from the driver side exhaust head pipe downstream of the manifold but ahead of the cat. GM puts a shield of this waffle-patterned metal around the head pipe. I suspect these shields are for both thermal and acoustic attenuation. These shields are clearly installed in a sloppy manner as the seam on the driver side unit was not closed together whereas the one on the passenger side was closed. The noise is coming from the actual head pipe and is escaping from the gap in that shield.
If you log spark timing from LT5s, at idle, you'll see the timing is about zero and sometimes even a little negative, ie: after TDC. That means some of the combustion is taking place after the exhaust valve opens and that makes the exhaust pulses pretty loud. With the shield(s) not installed properly, you hear them as a "chirp"
As you go off-idle, the spark advances, less combustion occurs after the exhaust valve opens and the chirping goes away.
In my opinion, the sound of a big-*** cricket trapped under the hood of my ZR1 is an rotten deal with a car that runs most people 140-large or more.
GM ought to either address the issue with revised cat assemblies having properly installed shields or...release a new cal for LT5 that doesn't have the spark so freakin' retarded at idle. Fat chance of the latter, I'd think so, GM...I'm waiting for my new driver side cat.
Call me when parts are available.
Last edited by Hib Halverson; 09-21-2019 at 11:24 PM.
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08-02-2019, 12:12 AM
#17
1878 aka "Bad Black and Yellow" has done that chirping crap since new, but only on the left side and it comes from down low in the engine.
A month or so ago, I got so curious about it, I rolled the car into the shop, got it up on stands, fired the motor then grabbed my stethoscope and rolled under the car on my spiffy new GearWrench creeper.
I found the chiping noise was coming from the driver side exhaust head pipe downstream of the manifold but ahead of the cat. GM puts a shield of this waffle-patterned metal around the head pipe. I suspect these shields are for both thermal and acoustic attenuation. These shields are clearly installed in a sloppy manner as the seam on the driver side unit was not closed together whereas the one on the passenger side was closed. The noise is coming from the actual head pipe and is escaping from the gap in that shield.
If you log spark timing from LT5s, at idle, you'll see the timing is about zero and sometimes even a little negative, ie: after TDC. That means some of the combustion is taking place after the exhaust valve opens and that makes the exhaust pulses pretty loud. With the shield(s) not installed properly, you hear them as a "chirp"
As you go off-idle, the spark advances, less combustion occurs after the exhaust valve opens and the chirping goes away.
In my opinion, the sound of a big-*** cricket trapped under the hood of my ZR1 is an f'ed up deal with a car that runs most people 140-large or more.
GM ought to either address the issue with revised cat assemblies having properly installed shields or...release a new cal for LT5 that doesn't have the spark so freakin' retarded at idle. Fat chance of the latter, I'd think so, GM...I'm waiting for my new driver side cat.
Call me when parts are available.
A month or so ago, I got so curious about it, I rolled the car into the shop, got it up on stands, fired the motor then grabbed my stethoscope and rolled under the car on my spiffy new GearWrench creeper.
I found the chiping noise was coming from the driver side exhaust head pipe downstream of the manifold but ahead of the cat. GM puts a shield of this waffle-patterned metal around the head pipe. I suspect these shields are for both thermal and acoustic attenuation. These shields are clearly installed in a sloppy manner as the seam on the driver side unit was not closed together whereas the one on the passenger side was closed. The noise is coming from the actual head pipe and is escaping from the gap in that shield.
If you log spark timing from LT5s, at idle, you'll see the timing is about zero and sometimes even a little negative, ie: after TDC. That means some of the combustion is taking place after the exhaust valve opens and that makes the exhaust pulses pretty loud. With the shield(s) not installed properly, you hear them as a "chirp"
As you go off-idle, the spark advances, less combustion occurs after the exhaust valve opens and the chirping goes away.
In my opinion, the sound of a big-*** cricket trapped under the hood of my ZR1 is an f'ed up deal with a car that runs most people 140-large or more.
GM ought to either address the issue with revised cat assemblies having properly installed shields or...release a new cal for LT5 that doesn't have the spark so freakin' retarded at idle. Fat chance of the latter, I'd think so, GM...I'm waiting for my new driver side cat.
Call me when parts are available.
