Anyone ever have this occur?

 

Driving along with the ac on and floor it, at a certian rpm, not sure since my 97 legacy Brighton didn't come with a tach. Anyway you get a sound that sounds exactly like a turbo BOV. I thought maybe a build up of pressure then releasing, but I'm still baffled.

 

Then a random power loss, without the ac on, almost like a quick missfire without a code. It has a new coil,plugs,new oem wires. My guess is maybe my alt is on its way, or something else. I get random power strangeness, now and then the dash lights will cut out(only happened twice in two years, fans kick on and the headless go dim. Etc.

Along with a random rough idle, I have ran a bunch of grounds and that helped some. I may do a comp test next week just to confirm no burnt valve.

Does it only make the sound with the AC on?

How well does the AC work? In my 96 the AC ran low on refrigerant and I guess oil too. After a while running hard to try to keep the car cool it would start to make a faint bearing noise that got a lot worse when I really got on the gas. I topped up the refrigerant but never added oil. durr. It was fine for a year like that but the compressor seized up on the new owner 5 months after selling it.

Have you done anything like... change the air filter?

 

Sounds like you may ehave a vac leak.

 

Some AC systems have a saftey valve if the pressure gets too high, I dont know if subaru has one off hand (I had an escort with one).

 

When was the last time the AC was serviced? Does it blow cold?

I just bought a 99 impreza L , & when test drove, it sounded just as you described. I thought it had a turbo also! I do have a cel for a code about evap, so its probably a leak somewhere. I hope it not the ac or alt.

My 98 OB did the same thing. I did it for several years and nothing ever stopped working so I wouldn't worry about it too much.

air filter is pretty new and clean. I went through and looked for vac leaks found one and fixed it, probably should get in deep to look for more.

Where was leak?

Broken line from the map sensor to the manifold. Got a feeling there is another somewhere, along with an old alt.

Yup at idle I hear the rear of my alt making strange noise.aprox 144k on odo.