Performance problems, Boost Leak symptoms without the boost leak.

[Goingnowherefast]

Reposting in a cleaner format in hopes of getting a solid answer. Logs incoming...

Here's my issue:
1. Leaking air sound for a while now in boost and vacuum.
2. Low boost readings from boost gauge.
3. Generally inconsistent boost, sometimes it'll spike 15psi, others ten, usually drops to 5psi by the end of pull.
4. Rough idle and jerky power band when MAF is connected.
5. All problems amplified with install of golf R IC and unmodified golf R hoses (rough idle only present after IC install).
6. VW dealers can't communicate with my ECU.
7. Underboost Code P0299

Here's what I've done:
1. Gotten it boost leak/vacuum tested (no luck)
2 . Replaced DV with Rev D
3. Deleted noise pipe
4. Checked more boost lines and tightened fittings
5. Blocked PCV w/ BSH stage 1 block off
6. Replaced MAF w/ one from another FSI car, no change
7. Unplugged MAF as it runs better without

Solutions I can think of:
1. Turbos going bad
2. N75 is bad
3. Leak from inproper IC install w/ unmodified golf R hoses
4. Bad vacuum leak

Help a brother out because I'm at such a loss right not. I'm actively looking for vagcom around SW michigan area. Thanks in advance.

 

[GIACUser]

Notes are nice and neat and easy to understand what you are seeing and what you have done so far but it is not enough information to diagnose your problem with accuracy.

Having said that, looking at #1 and #2 sure sounds like you got a hole somewhere between the turbo and the motor. Logging will help you narrow it down. Once you get the cable, log boost, timing, fuel to start. Generally I do a 4th gear run from 2500 to 6500 for each of those blocks. Needless to say that is very high speed and dangerous if not done on a track but it is the kind of run that will net you the proper information when the engine is under load. You can also do 3rd gear runs (uphill is best because it will put more load on the motor). Or best, do all your logging on a dyno.

 

[Mighty20t]

3. Leak from inproper IC install w/ unmodified golf R hoses

This would be my guess. Especially if it started happening after you installed IC.

 

[Jerseynoob]

3. Leak from inproper IC install w/ unmodified golf R hoses

This would be my guess. Especially if it started happening after you installed IC.

When the intercooler hoses were installed, did you replace the gasket on the intercooler piping where it meets the turbo outlet pipe?

I ask because after my shit intercooler install, the installer couldn't find the leak, which caused all kinds of havoc, they shrugged me off, and when I went to their competitor, they found it right away, the original installer failed to replace this gasket.

 

[golfballer78]

perform boost leak test?

 

[Goingnowherefast]

perform boost leak test?

Already done, nothing found.

When the intercooler hoses were installed, did you replace the gasket on the intercooler piping where it meets the turbo outlet pipe?

I ask because after my shit intercooler install, the installer couldn't find the leak, which caused all kinds of havoc, they shrugged me off, and when I went to their competitor, they found it right away, the original installer failed to replace this gasket.

This would be my guess. Especially if it started happening after you installed IC.

Having said that, looking at #1 and #2 sure sounds like you got a hole somewhere between the turbo and the motor. Logging will help you narrow it down. Once you get the cable, log boost, timing, fuel to start. Generally I do a 4th gear run from 2500 to 6500 for each of those blocks. Needless to say that is very high speed and dangerous if not done on a track but it is the kind of run that will net you the proper information when the engine is under load. You can also do 3rd gear runs (uphill is best because it will put more load on the motor). Or best, do all your logging on a dyno.

Thanks for the replies guys. I just ordered a gasket for the IC outlet hose and will replace it asap. That being said I stumbled upon this thread: http://www.golfmkv.com/forums/showthread.php?t=89663 If you guys want to take a second a read through it, it appears to have literally all the same symptoms as mine and sounds exactly the same. Maybe its the turbo itself? I do have a K04 on-hand

 

[GIACUser]

Already done, nothing found.





Thanks for the replies guys. I just ordered a gasket for the IC outlet hose and will replace it asap. That being said I stumbled upon this thread: http://www.golfmkv.com/forums/showthread.php?t=89663 If you guys want to take a second a read through it, it appears to have literally all the same symptoms as mine and sounds exactly the same. Maybe its the turbo itself? I do have a K04 on-hand

Yeah, it could be a loose turbo causing your leak. Let us know what you find.

 

[Goingnowherefast]

Yeah, it could be a loose turbo causing your leak. Let us know what you find.

It would explain why the shops that smoke test it can't find anything except for near the DV (pretty much at the turbo). I'm gonna take a look at it this weekend and replace the IC gaskets while I'm at it. If that doesn't work I figure I might as well swap the turbo out, since the K04 will have a new wastegate and N75 anyways (two possible causes of incorrect boost).

I'm sure this has been done a lot but have you guys heard of very many people running the K04 on stock tune for a while, obviously being careful not to go into boost? I may have to wait to get my DM programmer in.

 

[GIACUser]

It would explain why the shops that smoke test it can't find anything except for near the DV (pretty much at the turbo). I'm gonna take a look at it this weekend and replace the IC gaskets while I'm at it. If that doesn't work I figure I might as well swap the turbo out, since the K04 will have a new wastegate and N75 anyways (two possible causes of incorrect boost).

I'm sure this has been done a lot but have you guys heard of very many people running the K04 on stock tune for a while, obviously being careful not to go into boost? I may have to wait to get my DM programmer in.

Yes you can run it with stock tune and just as you said take it easy. You can boost the car some just take it lightly.

 

[Goingnowherefast]

So this is my hot side ic hose... anyone want to guess what should be there but isnt?

 

[Strieg]

O ring

 

[snobrdrdan]

Well, that's an easy fix :thumbsup:

 

[GIACUser]

That should have been a super easy one to find. Simply spraying a little starter fluid around joints probably would have found this in about two minutes.

 

[Goingnowherefast]

You know what the funny thing is? This passed a boost/vacuum leak test at multiple shops.

 

[GIACUser]

You know what the funny thing is? This passed a boost/vacuum leak test at multiple shops.

Well tell us how the thing runs once you get it that O-Ring in place and hope whoever put it together didn't forget something else. Glad you found the culprit.