# A/C Hissing Sound

**URL:** <https://community.cartalk.com/t/a-c-hissing-sound/66327>\
**Category:** Maintenance/Repairs\
**Created:** [July 17, 2011, 11:46am UTC](https://community.cartalk.com/t/a-c-hissing-sound/66327 "2011-07-17T11:46:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jaspersysevilla](https://avatars.discourse-cdn.com/v4/letter/j/6bbea6/32.png) [@jaspersysevilla](https://community.cartalk.com/u/jaspersysevilla)\
**Post date:** [July 17, 2011, 11:46am UTC](https://community.cartalk.com/t/a-c-hissing-sound/66327/1 "2011-07-17T11:46:14Z")

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Hi,

When I turn on my a/c, it gives this short hissing sound for a second or two before it goes away. Then along the road i heard random hissing sounds (not often nor consistent, just happens every now and then) that lasts for a sec or two.

Could this be a future problem or is it normal?

Thanks.

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**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\
**Post date:** [July 17, 2011, 8:06pm UTC](https://community.cartalk.com/t/a-c-hissing-sound/66327/2 "2011-07-17T20:06:28Z")

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Of course, year make and model are always a great benefit. But, AC cools when refrigerant escapes through a valve or orifice, spewing from a liquid in excess of 200 psi to vapor at 30 psi.

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**Author:** ![oblivion](https://avatars.discourse-cdn.com/v4/letter/o/3ab097/32.png) [@oblivion](https://community.cartalk.com/u/oblivion)\
**Post date:** [July 17, 2011, 10:18pm UTC](https://community.cartalk.com/t/a-c-hissing-sound/66327/3 "2011-07-17T22:18:00Z")

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This is the normal sound you will hear in the cabin when the compressor cycles on and off. On some cars it’s more noticeable than others.