beejohn

This is a repost for the monday crowd with more info:
Okay, I'm sure all of you are sick of me posting my boost leak problems. But here is the continued story one more time.

1. Replaced Vac lines
2. Pressure tested no leaks
3. checked all hose (yes, even the famous L hose for the brake booster)
4. Took it to the stealership

So, the dealership says "holy **** your car is boosting like mad"-- yes it is, but the main torque curve between 2k-3500rpm is no longer felt that I initially felt the first few days.

Anyways, they checked everything they could. Ran a test on the N75 valve, checked all hoses, did pressure tests, pressure tested the bpv. Couldn't find anything. Said the car is running perfectly fine.

When I first brought it in they saw the engine was throwing a lean code, so they replaced the MAF Sensor thinking that was the problem. Problem still not fixed.

The tech actually was trying to convince me that the sound is normal because he can't find anything wrong with the car. It clearly sounds like air is escaping from somewhere right between those RPMs in full throttle. He said it sounded like the turbo sucking in air because of an overboost problem (i swear it really sounds like a lot of air leaking out and thus a loss of power).

I did a log of block 115 (i think that's it, the boost block)... The requested vs actual boost lags behind in the RPMs where I used to feel the chip the most (and subsequently, this is the same point where I hear the noise). I swear there was more power the first 24hrs I had it chipped (A LOT MORE TORQUE in 2k-3k). I have several logs of 119-115:
This one goes up to 7000rpm. Boost lags in the beginning, spikes higher, and goes below requested at the end. (The same exact issue Silver Streakin' is having--I'm guessing the wastegate is stuck in one position, causing the turbo to lag at spool up, overboost, then not spool enough at the end)
<a href="http://sdcc17.ucsd.edu/~bhemraja/a4/115-119.CSV">http://sdcc17.ucsd.edu/~bhemraja/a4/115-119.CSV</a>
The rpms don't go as high in this one, but still the same pattern.
<a href="http://sdcc17.ucsd.edu/~bhemraja/a4/119-115.CSV">http://sdcc17.ucsd.edu/~bhemraja/a4/119-119.CSV</a>

Here is a graph:
<img src="http://sdcc17.ucsd.edu/~bhemraja/a4/boost.gif">
Yellow is requested boost, white is actual boost.
As you can see, it lags behind in the beginning, spikes higher, then tapers off after 5000rpm.

I was also requested for a log of block 032, there are results in this file for two different days:
<a href="http://sdcc17.ucsd.edu/~bhemraja/a4/032.CSV">http://sdcc17.ucsd.edu/~bhemraja/a4/032.CSV</a>

And here is a log of blocks 003/031/054:
<a href="http://sdcc17.ucsd.edu/~bhemraja/a4/003-031-054.CSV">http://sdcc17.ucsd.edu/~bhemraja/a4/003-031-054.CSV</a>

I think it is either a high pressure leak (when boosting around 20psi) because the leak is ONLY AUDIBLE from about 2250rpms to 3500rpms, or the wastegate problem.
Anyone with some hoses to check for high pressure boost leaks?

Also, since the tech keeps telling me this leak is "normal" (yeah right) is there anyone in the Orange County/San Diego area with a 2001 GIAC chip who would like to ride in my car/let me ride in theirs to help me figure out whether or not I'm just crazy or this noise is normal.

I will check in a few more days if the car throws a lean code again (which is an indication of a boost leak right?)

Please let me know if you guys need any other info on the car from me.

Thanks a lot.

RKA

There is a boost leak, and you can hear it. Off throttle (vacuum instead of boost), that leak is allowing unmetered air in, and that's causing your lean code.

Keep looking...you'll find it. If you get frustrated, take it to EuroTech (?) in Santa Monica.

JA4T

did you check the following parts: diverter valve(leaks or sticking piston), N75-wastegate solenoid(known for error), or wastegate rod problem(although,common mostly in 97 turbo)???
J

JA4T

Ron Wood is basically known as an Audi god,,,he can fix it. He is more than reasonable in his prices also.

VW Specialties
Ron Wood
714-848-4336
Huntington Beach, CA.

J

beejohn

are you sure that is the number? i just get a "answering machine is off" message after 1min of ring

beejohn

i think thats their fax... 714-848-3766