# 2008 Chevrolet Impala - Starting issue

**URL:** <https://community.cartalk.com/t/2008-chevrolet-impala-starting-issue/162055>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet\
**Created:** [March 29, 2020, 6:36pm UTC](https://community.cartalk.com/t/2008-chevrolet-impala-starting-issue/162055 "2020-03-29T18:36:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![PatrickWilliams](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@PatrickWilliams](https://community.cartalk.com/u/PatrickWilliams)\
**Post date:** [March 29, 2020, 6:36pm UTC](https://community.cartalk.com/t/2008-chevrolet-impala-starting-issue/162055/1 "2020-03-29T18:36:28Z")

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Ray…love your column…I have an engine problem,when I start  
my car, when it has been sitting for more than 6 hours…  
mostly in the morning at first start & when I go home from work after 8 hours. There is a noise…sounds like a siren…really…the engine starts & there is no check light…& lasts for about 30 seconds…If I get out & raise the hood…the sound has stopped. on 9.12.19 I had a check engine light with a PO411 error…my mechanic replaced the Air Check Valve at $800…wow…but the check light went out & all was good until this siren noise…started about a month ago…  
What is your fix?  
Thanks,  
Pat…somewhere in the middle of California

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [March 29, 2020, 8:08pm UTC](https://community.cartalk.com/t/2008-chevrolet-impala-starting-issue/162055/2 "2020-03-29T20:08:31Z")

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What you might be hearing is the secondary air injection pump for the catalytic converter.

![](https://global.discourse-cdn.com/cartalk/original/3X/9/e/9e5d0bdfafffa92be81822cc9a55ad1e68c7b5c1.jpeg)

When these start to fail, they can sound like a siren.

Tester