Brayton

Update: I ran a boost leak test. Did the tennis ball and compressor test. Didn't find any leaks. My friend had a scan tool and found out my throttle body is running at 75%. Would this create the substantial decrease in performance? How can I fix this? Vag-Com?

aTOMic

I'm not sure what that means, but yes; if there IS something wrong with your TB, VCDS would probably show it. You're on the right track in trying to connect with a local VCDS owner.

4 PSI is odd, I expected zero (normal is about 8 PSI I think). IIRC there are some vacuum lines which carry less than full vac/boost; you didn't tap one of those, did you? (no offense, just trying to cover all the variables).

My car was overfilled by a quart by the geniuses at HALLMARK VW, MADISON TENNESSEE (don't get me started, again ). My puck valve was full of oil, and there was a lot of oil in the intercooler and in the crossover tube (big metal pipe below the radiator) and into the TB, too. It (TB) still needs cleaning at each oil change, then it runs better. I take off the crossover pipe (lowest point so that's where most of the oil collects) and drain a tablespoon or so. When you had the intake apart did you see any oil? maybe that's messing with the TB, causing the reading your friend's scan tool picked up.

You might consider searching Passatworld.com, too. there are a high percentage of 1.8T owners there.

Keep up the good work!

-Tom

Brayton

I spliced that line that goes from the DV to the intake (I believe that's what the line is) at this point I'm sure it's either my TB or its just an old turbo. Thing is 14 years old so I wouldn't be surprised if its just dying. Just an excuse to slap on a K04 and get my ecu flashed. Im goin to contact a dealer today to get a price on a scan if I can't get a hold of anyone. Thanks for the support guys!

Prospeeder

Try pulling a vacuum on the DV valves little vacuum line, if it doesnt hold, the diaphragm is ripped. If its springs broken, it will just open right up and bleed all your boost back to the front of the turbo. Also if the little solenoid that controls the wastegate isnt operating correctly, the vacuum lines have collapsed or been blocked or are rotten, or its just bad, you wont be getting much boost.

BTW turbos dont just get tired, they work till they smoke like hell or something breaks. my 200 Avant has 270k on the original engine and turbo and a 1.8bar spring and chip from 70k miles according to the giant folder 6 inches thick of paperwork for the car. And it still pulls hard for a big old wagon haha

Brayton

I just got done cleaning my throttle body and throttle body temp sensor, still no results. :/

You're suggesting I disconnect the vacuum line from the DV?

Brayton

Also, I'm meeting up with a fella from VWV and he's going to help me realign my TB. I'll make sure to get any and all codes and I'll post them up here later.

aTOMic

Be sure to tell someone where you're going, LOL!

Brayton

Finished the VCDS scan. I think it said my boost pressure control valve was bad, my throttle body position sensor was bad, and my transmission throttle body sensor (or something like that) everything else was just minor stuff. Like my fuel sensor(tells me i'm empty at half tank) and my front passenger anti-theft sensor.

Would the PCV and TB position sensor cause these problems I'm having?

Brayton

Engine codes:
18010 - power supply terminal
P1602 35-10 voltage too low
17956 - boost pressure regulation valve
P1548 35-10 open circuit.

Auto Trans codes:
00518 - throttle position sensor (g69)
27-10 implausible signal

Does any of this look like the culprit to my performance issues?

4Driver4

There is no tool that identifies specific parts as "bad". Codes are clues. Simply replacing a part because a code is related to it is a bad strategy.