Hissing noise ?

[mark_b1981]

Hi all on my car when the econ is off I get a hissing sound coming from the air vents but when the econ light is on I don't get any hissing sounds atall does anyone have an idea of what this could be ?

I have a 53 reg 2.0 fsi thnx peeps

 

[mark_b1981]

Any ideas ?

 

[SootySport]

All I can think off is, when the econ light is off, the a/c is on and refridgerant is circulating around the a/c unit, maybe the refridgerant which also contains a special oil is what you can hear, there may also be air in the system if it has never been regassed causing a hiss. If you have not ever had a regas then it may be worth having done. A regas will extract all the refridgerant and oil, weigh it and refill the system with the correct amount of refridgerant and gas. Should cost about £45 these days.

 

[mark_b1981]

I've had the car just a year and it's been doing it for a while now but as far as I know it's not been re gassed couldn't see anything on the old receipts. I was thinking / hoping it may just need a re gas I checked on the Audi site and they charge £79 but as you said another independent garage should charge a lot less

 

[SootySport]

Had a listen to mine today and I can't hear anything like you say. I don't want you go spending money unnecessarily but it would be worth visiting an a/c expert and asking his opinion first.

 

[mark_b1981]

Cheers soot my car is booked in on Thursday to get my front pads replaced when I drop it off I'll ask the machanic to have a listen and see if he knows what it is and tomorrow I'll take some video footage of it and post it up on here

 

[SootySport]

Hope it's not something like this http://www.audi-sport.net/xf/threads/s3-2010-sportback-brake-servo-replacement-cost.257992/ just been reading about it.

 

[mark_b1981]

Oh no nothing like that the hissing noise only come through the vents when air con it switched on and when switched off the hissing stops completely

 

[Carefree69]

You sure it's not a snake?