My 2006 makes an intermittent hissing noise - usually after coming off the gas pedal. Seems to be worse when running the AC. Is this normal?

 

Could be the sound of your Rotary or Tranny. Its norm for you to hear the Trannys wind or as you put it hiss.

 

yeah we need some more info....MT or AT is it like air hissing or a humming? what year car? Location? Milegeage?

 

List your specs and mileage, and try to explain the area that you hear the noise. For example, front right tire, engine, shifter and so on. Specifics for noises are nice, I would know....I get customers saying the car laughs when turning and I work at a Toyota dealership (there high on pcp!) lol. We would love to help you out .

 

theres a snake in your engine bay

 

I have a 2006 MT Shinka with around 14K. The hiss will last around 2 seconds and souds like pressure dumping. Seems to come from under the passenger side dash/floor area and is more frequent when the AC is running. I live outside Charlotte and have recently lost a pet snake...

 

Engine running or shut off?

 

Most likely it's the A/C's expansion valve. It's located in the car on the passenger side. Either it's going bad or you're getting low on refrigerant due to a slow leak.

 

I have only heard it when the car is running. I think the AC expansion valve sounds likely. I will have the dealer check it out the next time I see them. Thanks for the help!

 

No problem, give them the specifics when you take it in though! Best of luck and let us know what is was!

 

mine makes that sound too... sometimes it even sounds like water is pouring out or something... almost like a drain..

 

Check for vacumn leaks too.

 

Yeah yours is definitely bad. lol

 

when i first turn on the a/c and rev i can hear a hissing sound then it stops after the ac runs for a little

 

hmm.... i guess ill have a trip to the dealer during the break.

 

It's your supercharger.. By your name it makes it seem like you have one