Help with Boost or Exhaust Leak - APR Stage 1

[DavidA3]

Hi everyone,

I've been trying to track down what I think to be a boost or exhaust leak on my 2008 A3 (TSI motor) - for the past 6 months. I'm Apr Stage 1, everything else is stock except a high flow air filter. Upgraded to Rev D DV Valve. (FYI - i started to notice louder turbo spool before the tune which prompted me to upgrade the DV with no change in loud spool noise)

At this point im not sure it a boost leak because I've pressurized the system to 12 PSI with no apparent leak. (my home made leak tester started to leak at 12 PSI so I couldn't test higher). My turbo spool sound had gotten progressively louder over the last few months to the point where I can hear it with my windows up. It's most noticable during initial spool up which seems to be taking longer also. As you can see by my logs, my N75 duty cycle is very high, only dropping from about 3k rpm to 4.5k rpm.

Even in stock mode, I can hear the turbo spool loudly. I'd like some comments on the attached log... I've got the Micro-Can connector so my data resolution isn't all that great.

I'm not sure what my airflow should be at stage 1, but 165 g/s seems low which makes me think I have an exhaust leak and the turbo can't spool properly even with the wastegate fully closed...

BTW - I'm at 2400 foot elevation and the ambient pressure here is about 920 mb. Air temperature at time of logging was 91 degrees. This was the first run after a slow freeway cruise, so I don't think heat soak was an issue.....




http://dl.dropbox.com/u/46000817/DT_...91ambient.xlsx

[DavidA3]

A bit more information from today...

check valve on front PCV is okay, Inspected connections from turbo outlet and pancake pipe, removed rubber inlet and outlet IC tubing then cleaned and re-installed - all looks okay. (except for the three tablespoons of oil!!)

Visually inspected exhaust side of turbo for visual signs of soot - none found.

Block 32 data is -.7 and +5.2


I'm beginning to think it might be the turbo going bad... any thoughts?!?!?! Damn TD1 campaign!!

[sfdxsm]

I don't have much to offer except your symptoms sound just like mine. 7000 miles, APR stage 1, etc. Same kind of problems.

I never found a solution however my car has been getting worse - now the computer keeps freaking out. Resets the clock, comfort settings, throws ESP and TPMS errors then clears out. Really odd no codes for me either.

I had the similar turbo noise before my APR flash too though and Audi couldn't find a thing. My car is a CPO too.

[DavidA3]

SFDXFM - Very interesting that I have a small oil leak on/near the turbo oil line just as you do......

[DavidA3]

Thank you Rob at APR!! I sent him over my logs and within an hour I heard back from him.. Wow - that's great customer service and shows dedication to their product and brand! It makes me feel comfortable about eventually going K04...


It seems that given my elevation (2500 - 3000 ft and high temperatures) my logs look normal. Probably my fault for comparing my situation to someone at sea level with cooler temperatures. Maybe its time for a new IC!!

[Rob@APR]

Glad I could help. If there is anything else, feel free to contact me.