I know I have a Countryman, but posted this here to get more eyes on it since it could apply to any 2nd gen.
Ok everyone, I need some advice. I recently finally found a way to test the turbo vacuum system for integrity and the vacuum pump. Pump seems to test ok, and holds vacuum after shut off.
To test the integrity of the lines and vacuum reservoir, I unplugged the vacuum hose from the wastegate actuator, and connected it to a vacuum gauge. When the car is running, it has vacuum, though possibly a little weak, not sure. But, as soon as I shut off the motor, the gauge fell instantly to zero. From what I understand, it should hold vacuum after shut down and at most, bleed off very slowly. Mine just goes instantly to zero.
I figure that this is telling me that either a vacuum line or the reservoir is leaking. I had planned on replacing the vacuum lines anyway and checking the reservoir visually. But now I’m sure something is wrong there, I wonder if I should still do the lines, and if the tank is cracked or something, I could probably epoxy it for a week until I get a new one here.
Or maybe I should wait and do it all at once?
What do the experts here think? Am I on the right track? What do you suggest?
I originally started digging into this, because of a small hoot/teakettle sound under really light boost (under 8 psi). It’s never constant, but I can pretty much make it happen with finesse on the pedal. Heavy boost.... no issues at all! No codes either.
Any thoughts? Does it seem like I’m on the right track?

 

I have a member with what we think is boost issue. I test 3 minis and all of them will suck the waste gate upone starting. Once you turn the car off, it returns instantly. The vacuum is help between the valve and vac pump not after. This is my observation.

 

Interesting, it says here that they should still hold some vacuum. Like when I disconnected the brake booster line, it was holding vacuum, I heard it equalize when I removed it. https://www.nomaallim.com/turbo-vacu...diagnosis.html
Im not sure now! Lol

 

I didn't pay attention to the booster line. But i do know the vac line going to the canister will have vacuum. The other one going to the gate, nothing.

While testing (cold engine), we saw the gate actuating as you rev up the engine. His countryman wasn't doing it, although his engine was hot.

As you mentioned, we didn't have codes. Also keep in mind the acceleration on the All4 model is slower than FWD.

 

MrGrumpy, if you'll clean up your mailboxes, I can respond to your PM. Let me know when it's ready?

 

Sorry about that, I didn’t realize it was full. It’s empty now

 

I’m aware of it’s slowness, lol. No the whole issue has been a funny little whistle noise, that has flummoxed me for a while now. But I believe I’m slowly narrowing it down. I have it torn apart right now. Running new vacuum lines. I tested the vacuum reservoir and it holds fine, so one more possible culprit is eliminated, lol. It may well be a cracked line, they are original and it’s got some mileage on it, so it’s a good preventative thing anyway.

 

Ok, well changing out the vacuum lines has definitely made an improvement, I must have had a bad line for one thing. It feels pretty good, the turbo sounds good too and seems to be spooling a tad quicker, but maybe that’s just me? The other “whistle “ issue is, unfortunately, still present. But I think I may have tracked that down a s well. I can’t really explain why, but I have been suspecting the vacuum lines, reservoir, or boost/pressure converter. Well, new lines, and the reservoir held vacuum perfectly when I put a vacuum pump on it.
So...... I’m left with this..... I pulled out the pressure converter and took a look at it. Unfortunately I do not know how to really test it off the car. But as I was checking it out, I noticed it has a ..... thing on it, with what appears to be vent holes on both sides. I was curious if that’s what it is (still not sure) but I rigged up a breathable cover from and old rag and taped it over it. Guess what? The sound now appears slightly muffled.
so I suppose my trick will be getting my hands on a used one to pop in there and see what happens. If anyone has a line on one for cheap, or an extra they are willing to part with, hit me up! Lol
What do you guys think? Does this sound even sort of plausible?
here is a photo of it:

Those holes are on both sides

Front of pressure converter. The round thing in front is what I’m talking about.

Running the vacuum lines

All buttoned up and you can’t really even see the blue vacuum lines! Ha ha If you look close at the wastegate actuator you can see one! Lol. But hey.....they match!