Boost leak symptoms but no boost leak found.

[Bunnspeed]

Dudes peaking at 16 or 17 psi also have aftermarket ICs. Check the connections, because these can be a source of leaks. I am pretty sure my ATP FMIC is the reason my car almost never goes above 19 or so PSI, whereas I used to spike around 24. A little oil seepage around some of the connections would seem to confirm that I have leaks at these points. These leaks may not be present unless the car is really loaded up and the turbo is spooling hard enough to stress connections that would be leak-free at lower psi levels.

 

[Vageline]

those anybody know how can i tell if my diverter version D is broken when i pull it out...what should i look for... sorry for the threat jack

a rev d will usually have a crack on the plunger and the rev c will have a ripped diaphragm... usually but can have crack elsewhere.

if you pull it, youll be able to tell really easy... usually. i say usually cause nothing is 100%

i couldnt find images for a reference except for the diaphragm dv... i dont feel like looking anymore for the rev d, but a little searching and youll find a pic for a reference... but you dont need a reference, its really easy to tell if one is cracked

 

[madd791]

a rev d will usually have a crack on the plunger and the rev c will have a ripped diaphragm... usually but can have crack elsewhere.

if you pull it, youll be able to tell really easy... usually. i say usually cause nothing is 100%

i couldnt find images for a reference except for the diaphragm dv... i dont feel like looking anymore for the rev d, but a little searching and youll find a pic for a reference... but you dont need a reference, its really easy to tell if one is cracked

Thanks ill check it....:thumbsup:

 

[sikkony]

Dudes peaking at 16 or 17 psi also have aftermarket ICs. Check the connections, because these can be a source of leaks. I am pretty sure my ATP FMIC is the reason my car almost never goes above 19 or so PSI, whereas I used to spike around 24. A little oil seepage around some of the connections would seem to confirm that I have leaks at these points. These leaks may not be present unless the car is really loaded up and the turbo is spooling hard enough to stress connections that would be leak-free at lower psi levels.

I already did a pressure test on the system. There's no leak up to 20PSI.

Update:
Here are the logs I attained from VAGCOM.

I don't know if my boost problem is from my misfire on cylinder 2. Any thoughts?

 

[sikkony]

Update:

To those wondering in regards to the OEM DV (rev d) being the culprit or not: I can feel an improvement of power. DV rev D only held 8psi. DV rev b allowed the boost to taper from 16 or so PSI down to 10PSI. A good improvement.

Misfire I highly suspect is injector related since spark plugs and coil packs are fine. I will look into it later.

Boost leaking symptom still at hand, I think it's narrowing down to N75/actuator related. I will need to double check if the intercooler is leaking.

 

[dark_knight]

I have a similar problem as you, car feels slow but no boost leak problem. I logged the car and found out my fuel pump isn't holding enough pressure. I'm guessing the seal is leaking. ...my question is, would that cause the car to be slower?

 

[Bunnspeed]

I have a similar problem as you, car feels slow but no boost leak problem. I logged the car and found out my fuel pump isn't holding enough pressure. I'm guessing the seal is leaking. ...my question is, would that cause the car to be slower?

I would think so. If higher-than-stock fuel pressure is needed to keep up with the fueling needs of a modded FSI car, than lower fuel pump pressure would make it slower. If your car isn't modded, then lower-than-stock fuel pressure presumably wouldn't be able to keep up with the fueling needs of the stock motor at WOT, so it'd still be slower.

 

[madmortar]

Any update?

 

[Savir04]

OP, sorry about this off topic question, what graph proccessing software are you using? it doesnt look like exel....

 

[madmortar]

seriously...any update?

 

[mushages]

Looks exactly like my logs

Sent from my HTC One X using Tapatalk 2

 

[lankfert]

I am going thru the same problem now. This thread seems to be the best out of all my searches.

Has there been any conclusion?

 

[sh00k0nes pt. 2]

Bump

 

[Stranded in Daytona]

If you havent' already, find someone with VCDS and do actual data logs. Log your fueling and boost...

I had the same problem. Boost would spike, but fall down to about 8 psi and hold there. No pressure leaks, DV was good and everything else was fine. I was getting CEL's and the codes throwing were indicating a LPFP issue.

After data logging today, I found that it was actually my high pressure that was giving me issues.

At boost, my requested HPFP was 110mbar, and I was only receiving 17mbar. My oem hpfp has 163K on it, so it's probably worn out. Gonna swap another oem one on there this week and see if it fixes my problem.

my car is Stage 2 Unitronic btw.

 

[Stranded in Daytona]

Also, you need to do your pulls from 4th gear, starting at 1500 rpms. Not second gear.