Turbo Noise and Boost issue

[mickel1138]

Hi,

Not too long ago I had a CEL of P1110 (if I remember correctly). The code most likely had to do with the Turbo Bypass Valve. So I ordered one. Ultimately it ended up being a vacuum line. (it disintegrated.)

After I replaced the vacuum line, by Turbo was working really well, super fast cycles, the boost needle was entering the first part of the red zone, it had power that I never knew it had before.

After some time it adjusted, and the cycles become slower and the needle at times barely touched the red area. I guessthe ECU figured things were back to normal.

Since I still had the new bypass valve, I decided to change it anyway. Took about 5 minutes, and I also tightened the turbo pipe a bit, it was a little loose (a 10mm nut).

It didn't get the power back I once had after replacing the vacuum line, it may cycle a little faster now. But just about when I almost hit maximum boost, about a little past the middle of the orange section, I hear a noise, it's like a hooting noise which goes away when the boost needle moves just a little bit further.

Now what is going on? Did I do something wrong with the valve, maybe I should but the old one back on? A leaking hose maybe? The airfilter is fairly new.

I'll see if I can make a video soon.

[Chris 9-5]

The hooting noise is a split rubber diaphram in the bosch dump valve:



The valve needs replacing.

[mickel1138]

This is really stupid, it's supposed to be brand new. I got it from a box.

I guess it'll just put the old one back on.

I checked both valves with a vacuum pump, and blowing in them. Both appeared the working fine. The "new" one felt like it had a harder spring.

Thanks Chris.

[Chris 9-5]

Is the noise still there with the old one on?

[brewtide]

Sometimes at the transition between vacuum and boost, my car will make a funny 'whale' sound. I've heard / know the blown out recirc valve noise, and it's different.

Is it just when you're riding the line between little boost and vacuum?

_ben

[mickel1138]

Brewtide, yes that sounds about right.

Chris, the NEW one is making the sound, I haven't put the old one back on, it didn't make any noise before as far as I could tell.

[mickel1138]

On my way home I make a little video clip.

http://www.youtube.com/watch?v=GmXZ9mgOXgA

See if that helps...

[mickel1138]

Replaced the Boost Valve, back to the old one, noise is gone!

Thanks everyone...