I've noticed a strange hissing/whining noise coming from the passenger side of the engine when I turn on the AC.

 

Maybe air in a line, a pump, or...any ideas?

 

Thanks

I've noticed a strange hissing/whining noise coming from the passenger side of the engine when I turn on the AC.

 

Maybe air in a line, a pump, or...any ideas?

 

Thanks

 

Obviously, diagnosing the "whine" noise on the passenger side without being able to actually hear it is rather difficult. Any whining noise on the passenger side of my Legacy GT, however, is usually my wife. Unfortunately, that whining is "normal operation."

All kidding aside, all A/C systems "hiss" slightly when the compressor is engaged. On a Subaru, you are hearing refrigerant "hiss" thru the expansion valve (at least I think your '03 uses an expansion valve) Some other vehicle A/C systems use an orifice tube to "meter" the refrigerant thru the evaporator core under the dash. You may even hear the "hiss" continue for a moment after the A/C system is shut down, as it depressurizes.

You have checked for obvious vacuum leaks or disconnected hoses, right?

My wife's '03 OBW JUST started doing this. It is now so low on refrigerant it no longer cools or defrosts. Perhaps it is a trend or known issue. I plan to put it in the shop in the next week or 2 for that problem and 1-2 other services. I'll try to rport back to this thread.

I actually haven't looked for obvious leaks yet. I'll see what I can find.

 

 

Thanks

Is your AC working all right?

Put the OBW in the shop yesterday. I'll report what they find.

 

 

just FYI

Bad hose, still waiting for the part. He didn't say which one. I asked if it was rubbing on something, he said no.

 

 

fyi

Looks like this thread is dead - but just to followup, both the inlet AND discharge hoses on the compressor had leaks. Reapired under warranty.

 

Carl