Need help troubleshooting 0 psi, no boost issue

[mickeyt_107]

Hello,
I was hoping I could get some help troubleshooting a boost issue that just came up on my 1999 1.8T. The car was driving fine the night before, and then yesterday when I started it up and started driving, I couldn't get past 0 psi and obviously the car is extremely sluggish.
I'm getting good vacuum so I don't think it's a leak in any of the lines.
There aren't any CELs, Vag-com is only showing a code for the throttle body that's been there for years.
My initial thought was that it was the N75 valve, so I removed the line from the valve to the wastegate to test it and still no boost.
The turbo only has 10k miles on it, bought it new from G-pop shop.

I'm really hoping my turbo isn't already shot, but it's hard to tell if it's spooling. What else could it be? Wastegate stuck open?

Any tips for what to look at next?

Mike

[grant19841]

Test wastegate by the blow and suck method, when u replaced the turbo did u buy a complete unit or just the cartridge?

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[mickeyt_107]

Test wastegate by the blow and suck method, when u replaced the turbo did u buy a complete unit or just the cartridge?

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I bought a whole new unit. By blow and suck method, do you mean attaching a longer hose to it and pressurizing it?

[grant19841]

Mouth over nip suck and hold tongue over nip to keep air in, same with blow.
It tests seals.

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[mickeyt_107]

So here's a quick update that may help further define the problem.

I haven't had time to work on the car but have to keep driving it since it's my only mode of transportation.

After taking it on the highway, the car will make 1psi at WOT, until about 5500rpm it can make about 5psi. This makes me think that the turbo may not be seized, and that it's a wastegate or hose problem. I'm hoping to test both of these soon. Does anyone else agree?

[zollaf]

the wastegate is simple valve. it is opened by pressure when the boost exceeds a set level. if you remove the actuator rod from the wastegate then you should be able to operate the gate by hand through its full movement. it may be seized in the open position. the pressure pipe and n75 valve open it, if it doesnt' open then you get an overboost situation, often resulting in limp mode, but to start with the car will boost perfectly. so you either have a wastegate stuck open or a broken turbo.