3 seperate problems or 1 big problem getting worse and worse?

Basically its been a whole bunch of issues with my turbo and Im wondering whether they are 3 seperate things or basically 1 big problem that keeps getting worse and worse. The following has happened to my turbo in chronological order...

1) Found out that when I hit over 130 km/h my turbo seems to cut out....after doing a long ass trip...and months later my car finally decided to throw out a code...it was scanned as an overboost problem.

2) In the winter my car shut off about 2 or 3 times randomly...friend commented that its a loose hose...

3) And finally...now the newest problem...I notice that when I hit a good 2800 rpm and let go of the gas you hear a sound almost like something powering down...im almost sure its a despool of the turbo and my friend told me it has something to do with my turbo allegedly decompressing?

With that in mind what do you guys think....I dont have a lot of cash ATM to dump into this. Id prefer to wait until summer if its driveable then Ill do it up...but if these are signs of a turbo in its dying moments then Ill have no choice.

You have a 2000 Jetta. Nice to know when trying to understand.

1) Overboost - possibly an N75, N75 hose, MAF, actuator. Got to diagnose by eliminating possibilities.
2) Probably relay 109 if it was a "clean" shutoff. Could be a loose wire. I don't know of a hose that would do this.
3) You let go of the GAS. No idea about the noise.

Jettamatic said:

Id prefer to wait until summer if its driveable then Ill do it up...but if these are signs of a turbo in its dying moments then Ill have no choice.

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Still summer untill the 21st! Don't rush fall and winter they will be here before you know it!

rdkern said:

1) Overboost - possibly an N75, N75 hose, MAF, actuator. Got to diagnose by eliminating possibilities.
2) Probably relay 109 if it was a "clean" shutoff. Could be a loose wire. I don't know of a hose that would do this.

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I pretty much agree.

At 130 km/h in 5th, you're right around peak vane position of the turbo if you floor it. If it's gonna go into limp mode, it'll be here. As said, it could be an N75 that is not venting vacuum properly. It is unlikely to be a vacuum leak between the N75 and actuator, as this would lead to less boost and a negative deviation. It could be stuck VNT vanes. If you drive it hard on a regular basis, it's probably not it. You can cycle the actuator manually by applying vacuum to the actuator, or with the computer at idle if you have VAGcom; engine-> basic settings-> block 10.

Cutoff is probably a Relay 109 issue. Sometimes they fail intermittently, work fine for months, and fail again at the most inopportune time.

Ok thanks guys...as for the sound its not the usual sound the car would make....it actually sounds like the turbo is losing pressure....try to imagine some high tech machinery powering down...you hear like a loud whine and thats what my car sounds like but there isnt an issue with power...like I said my friend had mentioned something about decompression...he isnt a mechanic or knows much about cars but he drives a 1.8T and mentioned hearing about something similar which is why he pitched that idea to me.

And one big question...will these problems get worse if I leave the car alone and drive it through the winter?

Sorry not to mention the sound. Probably just the turbo spooling down.

The relay is pretty cheap. I'd take care of that now.

The boost issues can wait, but if do the diagnosis yourself, it may be something equally inexpensive. The N18 and N75 are the same aside from the color, so if it's an N75 issue you can swap in your N18 for free, though then you might get (less serious EGR issues)

aNUT said:

Sorry not to mention the sound. Probably just the turbo spooling down.

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Is this normal though? I have not heard this sound in over a year that Ive been driving the car and it only recently begun.

that's hard to say, because I'm not sure we're talking about the same sound.

Can you make the car do it when you load the motor hard, the abruptly push in the clutch?

It's more prominent on cat-less cars; though I've heard it on stock exhaust systems especially if you try using the method above.

When we had an overboost code, it was a clogged intake - have you checked out that possibility?