Turbo overboost- LIMP / Vacuum Help Please!

Hi All,

Have a problem with my 2005 passsat 2.0 BHW going into limp mode while mainly accelerating onto the highway or going up hills. It also has a slight stutter occasionally and black exhaust/ smoke exits.

I hooked up my OBDelleven and it gave me these codes. I looked the codes up on Ross' website.

P3101- INTAKE FLAP MOTOR - OPEN CURCUIT/ SHORT

P3103- INTAKE MOTOR FLAP FAULTY - P3103

P0234- OVERBOOST TURBO

Last night I pulled the vacuum line off the turbo actuator and I had about 17" of vacuum. I will say occasionally when I rev'd the engine it would drop to 0 then go back up. I turned off the car tried again and revving the engine would only get 10". It seemed to be all over the place.

Then I reconnected everything, then proceeded to unhook the vacuum line from the firewall where it goes through over and across to the brake booster. I took a reading from there and with the feed line to the turbo and reservoir hooked up it was bouncing around 20" vacuum. When I used hose pliers to block that 3mm hose going to the turbo/ N75/ Reservoir system it held steady at 26" of vacuum.

I think my next step is going to replace all of the vacuum lines and N75 Valve. I was wondering if someone has the part number to order replacement parts as well as how much length of the 3mm hose and 5mm hose to use. I went to IDParts and they have 4 kinds of hose 3mm silicone, 5mm silicone, 2mm hard vacuum line black and 2m hard vacuum line clear. I did notice the pressure release hose coming from the N75 to the air filter box is plumbed with what looks like 5mm of N75 to hard line back to soft line going into the air filter box. I'm just confused on what materials to use, is this common or did the person who owned it before me just hack it together with that?

Does the hose need to be the braided style? or does just the silicone plain work?

Also going to try and look in the EGR and Anti shudder valve to inspect that the EGR isn't full of carbon and that the anti shudder valve is opening fully when on and closing when off. I will also disconnect the anti shudder and make sure it is open, I've heard the spring is supposed to do that. If not I will order new one. Will drolly try and drive with the anti shudder unplugged and see if that gets rid of my stutter.

Any help will be greatly appreciated as this limp mode is driving me crazzzzzzzyyyyyy! Thanks, A.J.

Also, found I have a split in the 90° hose going from the anti-shudder valve to the plastic hose tube providing air to the intake. Cant tell yet if the tube split is all the way through but will replace anyways.

Also, does anyone have the part numbers for the two check valves in the vacuum system?

The 90 degree hose could be all that's wrong. Got to replace it. For quick testing purposes, you could Gorilla tape it and clamp it. It might run much better that way.

Just figured I'd update what fixed it for me incase anyone has similar issues. Replaced the vacuum line and adjusted the VNT actuator shaft length per a write up on Kermatdi's website. Fixed the issue completely.