# 2008 Chevy Silverado 5.3 misfire only at idle on #2

**URL:** <https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995>\
**Category:** Power/Fuel\
**Created:** [April 22, 2019, 12:09pm UTC](https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995 "2019-04-22T12:09:54Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ChevySilveradoLtd](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@ChevySilveradoLtd](https://community.cartalk.com/u/ChevySilveradoLtd)\
**Post date:** [April 22, 2019, 12:09pm UTC](https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995/1 "2019-04-22T12:09:54Z")

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It runs great going down the road but if I stop at a red light it starts to miss I already replaced the coil spark plugs & wires and injector I’m lost

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**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\
**Post date:** [April 22, 2019, 1:19pm UTC](https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995/2 "2019-04-22T13:19:10Z")

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Have you run a compression test on the engine? That cylinder may be a bit worn and the low compression is causing a mis-fire. What did the sparkplug from #2 look like when removed?

And how do you know that there is a mis-fire on #2? Did the check engine light go on? Did you scan the codes and get a P0302? Or do you just feel it?

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**Author:** ![Scrapyard-John](https://avatars.discourse-cdn.com/v4/letter/s/f6c823/32.png) [@Scrapyard-John](https://community.cartalk.com/u/Scrapyard-John)\
**Post date:** [April 22, 2019, 10:37pm UTC](https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995/3 "2019-04-22T22:37:30Z")

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I bet that cylinder is one of the cylinders with a collapsible AFM lifter…but I don’t know for certain. If so, could be the cause. GM had a lot of problems with those lifters, especially in 07 and 08.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [September 13, 2019, 3:55am UTC](https://community.cartalk.com/t/2008-chevy-silverado-5-3-misfire-only-at-idle-on-2/138995/4 "2019-09-13T03:55:19Z")

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A test with a vacuum gauge could be a good precursor to running a compression test.

If not low compression then maybe a weak valve spring. I’ve seen this on Chevys a few times.  
A vacuum gauge would show a weak or broken spring.