Start up Whine/Whir on cold stsrt
Thread Starter
Cruising
Joined: Dec 2025
Posts: 14
Likes: 0
Start up Whine/Whir on cold stsrt
Looking to buy this 04 Z06. The owner let me know that this whine/whir is a new noise that he hasn't heard before and wanted to inform me. It only happens on a first cold start and only lasts for 20-30 seconds
This sounds very similar to my buddies C6 when you start it from cold with the hood open. Which leads me to beleive it might be normal. However the owner reporting it as a new noise, as well as it currently being at a shop to diagnose. Makes me think otherwise.
The shop currently thinks its an alternator, but im less convinced considering it goes away within 30 seconds. They can only test it twice a day due to the nature of it. Any ideas on what it might be? Or what to advise the shop to look for on their cold start tomorrow morning?
https://youtube.com/shorts/thZ0187c7h4?si=DtdU1wzNS9erhg7l
This sounds very similar to my buddies C6 when you start it from cold with the hood open. Which leads me to beleive it might be normal. However the owner reporting it as a new noise, as well as it currently being at a shop to diagnose. Makes me think otherwise.
The shop currently thinks its an alternator, but im less convinced considering it goes away within 30 seconds. They can only test it twice a day due to the nature of it. Any ideas on what it might be? Or what to advise the shop to look for on their cold start tomorrow morning?
https://youtube.com/shorts/thZ0187c7h4?si=DtdU1wzNS9erhg7l
Thread Starter
Cruising
Joined: Dec 2025
Posts: 14
Likes: 0
That is my thought possibly. Would be worried if the sound is too loud and indicator of issues. Given the car would come back to California and its a smog requirement would be only concern
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,406
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From: Cape Coral, Florida
Looking to buy this 04 Z06. The owner let me know that this whine/whir is a new noise that he hasn't heard before and wanted to inform me. It only happens on a first cold start and only lasts for 20-30 seconds
This sounds very similar to my buddies C6 when you start it from cold with the hood open. Which leads me to beleive it might be normal. However the owner reporting it as a new noise, as well as it currently being at a shop to diagnose. Makes me think otherwise.
The shop currently thinks its an alternator, but im less convinced considering it goes away within 30 seconds. They can only test it twice a day due to the nature of it. Any ideas on what it might be? Or what to advise the shop to look for on their cold start tomorrow morning?
https://youtube.com/shorts/thZ0187c7...dU1wzNS9erhg7l
This sounds very similar to my buddies C6 when you start it from cold with the hood open. Which leads me to beleive it might be normal. However the owner reporting it as a new noise, as well as it currently being at a shop to diagnose. Makes me think otherwise.
The shop currently thinks its an alternator, but im less convinced considering it goes away within 30 seconds. They can only test it twice a day due to the nature of it. Any ideas on what it might be? Or what to advise the shop to look for on their cold start tomorrow morning?
https://youtube.com/shorts/thZ0187c7...dU1wzNS9erhg7l
Sounds like your A.I.R pump…if your shop “thinks” if it’s an alternator find another shop !!…BTW, the C6 does not have this pump.
Drifting
Joined: Sep 2022
Posts: 1,308
Likes: 972
If it isn't posting a code, and only happens on cold start, then I wouldn't think it should be an issue for smog inspection.
Thread Starter
Cruising
Joined: Dec 2025
Posts: 14
Likes: 0
Sounds like your A.I.R pump…if your shop “thinks” if it’s an alternator find another shop !!…BTW, the C6 does not have this pump.
https://youtu.be/h1ttFWBYhAo?si=oKNRcKxO_TGU4OJK
https://youtu.be/h1ttFWBYhAo?si=oKNRcKxO_TGU4OJK
Thread Starter
Cruising
Joined: Dec 2025
Posts: 14
Likes: 0
Burning Brakes
Joined: Nov 2013
Posts: 1,076
Likes: 434
If it is the air pump, they aren't hard to find for replacements. I think I still have mine removed from my '02. If you needed it, I'd be willing to "sell" it you for the cost of shipping
Best of luck in your hunt for a Z!
Best of luck in your hunt for a Z!
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From: Dyer, IN
The AIR system will be disabled under the following conditions:
- When the PCM recognizes a condition and sets a diagnostic trouble code.
- When the fuel system is operating in Closed Loop.
- The AIR pump has been ON for 240 seconds.
- Engine Speed is greater than 2825 RPM.
- MAP is greater than 96 kPa (14 psi) with VSS over 96 km/h (60 mph).
- MAP is less than 20 kPa (2.9 psi).
- ECT less than -10°C (14°F).
- 3-way catalytic converters over temperature detected.
- Short and long term fuel trim (FT) are not in their normal ranges.
- Power enrichment is detected.
