hissing

Hi guys, I recently noticed that my A/C started making a hissing noise almost immediately after turning it on, the hissing also stops right after turning it off. When ON, the air coming out of the vents is also just slightly colder than ambient air outside the car, so it works, but just...

So I don’t know exactly what’s going on but after getting the timing chain job done. Now I start up my car and it hisses, some white smoke but that could be from sitting a while. I think it is turbo? Anyone know? Audi A3 weird sounds

2006 A3 2.0T fsi. So I’ve got a weird hissing noise and it’s NOT when I’m accelerating... It only happens above around 20mph, in gear and with no feet on the pedals. As soon as I touch the accelerator, even slightly it goes away. The hiss also goes away when I press the clutch in. I cannot find...

Hi, Hi have been reading a previous post in relation to this problem by rikkbb, great post and thanks for the info. However I was hoping that someone may be able to provide the following additional info?? How do I diagnose what component is failing? And where or how do I find the part number...