Im stumped, no boost for almost half a year.

Its just not boosting anymore, its been lacking any real power for around 4months now. New n75 (audi oem) new tfsi red coil packs, new plugs, new DV, new MAF (audi oem, exact for my engine code) pressure and smoke tested (yes, 2 different mechanics, both methods) no leaks (up to 18psi, blew to the TIP off in one test) no codes, and not boosting, feels like its in soft limp and can not for the life of me get it out. Resetting the ecu does nothing, Im so out of ideas and getting to the point where I may sell this thing.

Very rough idle (not dead coil pack rough, but rough), its missing, idle is fluctuating. It actually misses so heavily at idle sometimes quite often i can hear what sounds to be a mechanical clunk that makes the whole car shudder. (what is this??) It doesn't miss under load/acceleration however (what little acceleration there is) The DV is very quiet, and there is almost no induction sound, (when i first installed my 42dd pod it sounded like it would suck in a small child if they stood too close, now, its barely audible under any sort of load)

Its also drinking fuel, have gone from 600km to a tank to about 450km to a tank. Prior to this 4months ago, it was boosting hard, so much so that I was getting a ton of torque steer under WOT. Got a hole in my intercooler piping, put it into limp, fixed this right away, but ever since then its never ever come out of soft limp

There was a loud crunch from deep in the engine bay and a big puff of black smoke from the exhaust(just happened once) about a month ago under WOT trying to get some sort of power out of the turbo. I thought I had blown my turbo, but it doesn't sound any different and it didn't change the performance at all for better or worse. (also threw no codes)

When this all first began 4 months ago, I swear my turbo started sounding different, instead of a very clean whir and almost a buzz (that deep pressurised tone you can feel it producing under WOT) under acceleration, it became more of a whooshing sound, no more of that really heavy, sharp, really solid spooling (if these descriptions give you anything to go by) the sound it has made for the last 4 months is more like a weak whooshing, to me it sounds like the air is escaping the turbo before even gets into my system, its not spooling anywhere near as fast as it used to, there's no more demand for a ton of air as the almost silent induction sound would suggest.

But wouldn't either of my pressure tests have found a cracked turbo? Is my turbo dead? Im beginning to think its fried. Wouldn't codes be thrown if I was loosing air through a dead turbo?

whats the best way to check the manifold or waste gate? I gave the waste gate a good push and pull and there's no give which i know is a good sign. They're sure troublesome parts to get to, charge pipe off will let me see the top of the manifold but what about underneath? jacked up and torch kind of deal? Also, in terms of the wiring loom shaunevo6, hows this look for a good replacement? Also no, no codes, so quite possibly hot side! http://store.034motorsport.com/harness-update-repair-1-8t-4-wire-coil.html

can you shoot through a link to that one man

Since the issue there has been an obvious wastage "pfft" sound before the DV releases, which was an important factor i forgot to mention! The waste gate flicks open quite loudly (can really hear it open and snap shut) right before the DV does anything. With this sound in mind it almost feels as if the waste gate is creeping open then snapping shut when i let of the throttle. But it is definitely only a development that began 4 months ago with the initial problem.

and so far this is all fantastic info!! I was becoming so broken hearted almost given up on the thing, fingers crossed i can find this

I just used a ****** little hand held bike pump, connected it directly to the actuator, basically one little pump made the actuator move, I got half a second pump before it was completely open and I couldn't pump again. It didn't leak at all, stayed open (good sign?). I let the pressure out and it returned. But it opened amazingly easily? I thought I'd need to really give it a few good pumps, there's no psi gauge on the pump but, so little pressure to open it? Bad actuator? Am I actually understanding it correctly in terms of holding pressure?

My actuator spring is 5psi so I think it's behaving properly. I'll grab myself the wiring harness, however I'm running the BAM 225 engine, is the Ecs harness still ok?

I think the stock actuator is 5? it seems to be between 4-5 depending what forum you're on I can't pull or push it by hand which i think is a good sign? (no play at all)

My last VCDS scan came up with no codes, I was getting a max boost pressure exceeded code what all this began, the one synonymous with a bad n75, so got a brand new oem replacement, didn't fix it. My lappy with windows was stolen so having to wait until i can use my copy of VCDS again.

If the wiring harness was going, this would throw some sort of code right? a misfire code? I definitely need to do some logging, i think i can find what i need to log through these forums (?) but it would be awesome to have someone who knew exactly what they were looking at help me out!

As far as the turbo (actuator), it held pressure. When i gave it that pump, it opened and stayed open, slowly returning to its position as i slowly released the pressure. so the diaphragm is fine? but the spring maybe? If the penny has broken away would the turbo be making some really nasty noises? Would the couple of pressure tests Ive had done on the system have shown a manifold or turbo leak? (one was mighty high, right up to 18psi, no signs, or sounds, of a leak)

Ive replaced "absolutely everything" I can think of, I really want to narrow down if its the turbo, actuator or manifold, I can't afford to take a shot gun approach to this one I know Ive got an absolute ton of questions but you guys are frikin awesome, helping me think this one out a lot.

hi guys, I got my coil pack harness, any DIY's on how to wire in just the coil pack section? I'm going to cut off only what I need from this harness and bin the rest. Got it extremely cheap so no harm done. I think a fellow on OZaudi was going to help me out but he's dropped off the forum for a while so branching out Its the ecs harness for the 180hp engines, I was told its a fairly easy job to take the coil pack section of this and run it into what Ive already got.