Hey guys,

This is my first post so take it easy on me. I have 2000 (97K miles) A4 w/giac and 710N installed maybe 2 months ago. I also recently purchased the car.

Prior to chipping I thought to myself Dammm this car is very slow! (Which i was expecting with only 150 HP) but it was worse than I thought. So I quickly chipped it. After chipping the car felt a little better I thought that it would be OK until I am ready to do a turbo upgrade (next year).

Well a few weeks later I took the engine cover off and BOOM a busted vacuum hose. I was like hmmmm, I wonder if this is causing any problems. I put the hoses together and use a zip tie not expecting anything big, but then whoa!! the turbo was louder, more torque and much more enjoyable to drive. I couldn't believe I was satisfied before.

This lead me to wonder about other possible leaks due to failing vacuum hoses. I replaced all vacuum hoses with new silicon braided hoses from ECS tuning on friday. I got in car expecting to be taken to a new level and instead i got NADA! Boost felt like maybe 5-7 PSI. It was HORRIBLE!


I struggled with why it got worse after replacing broken hoses. I used VAG Locator to find someone to help me scan the car. The person only had the shareware version but we pulled "Charge Pressure Control: Negative Deviation" code. I pulled and cleaned the PCV valve, pulled the DV valve and tested it. Everything seemed fine. I spent the whole weekend working on the car with no luck.

As luck would have it (after searching audi world for instances of the above code). I found what seemed like the cause of all my problems.... a BUSTED L HOSE. I went to the dealership today, got the hose and replaced it............................... OH YEAH MORE POWER. The SOUND OF THE TURBO INCREASED....... TORQUE CAME EARLIER, LONGER, and MORE OF IT.

I was all happy until I realized that I still had a problem I noticed since i found the first boost leak (busted hose).

This is what my post is all about everything prior to this is just history. The car runs great, but if I redline 3rd, 4th, or 5th I lose the power. The boost goes back to an almost stock level. I can no longer hear the turbo, or feel the power... MAJOR DIFFERENCE.

At first I thought it was HEAT SOAK but it is not. I say this because all I have to do to get the power back is the turn the car OFF and ON again; instantly the power is back.

What is causing this guys? Another boost leak or some electrical component failure?

 

Well, I didn't read the entire post, but I'm guessing your going into limp mode. I also have a 2000 w/ GIAC, and it goes into limp mode if I get near redline. Once it goes into limp mode it will only boost at 5 psi, which is a third of what it normally boosts. This would explain your loss of power. After shutting the car off, and turning back on, it is back to normal.

 

OK thats sounds like my problem, but how do I fix it? How do I prevent it from happening (Don't say don't red line it)? I thought these cars only went into limp mode when boosting over 20 PSI i can't imagine that my car is capable of making that much boost. Additionally, I don't get any check engine lights.

What next?

 

I'm not sure, and it doesn't really bother me because I don't drive my car very hard. I think it may have something to do with your N75 valve. You might try upgrading it, but I'm just guessing. I'm sure someone that knows what they are talking about will chime in.

 

For the thirty-odd bucks I think it would be worth throwing a 710N in it and seeing if maybe that doesn't clear it up.

I won't bother pointing out that the redline is... well, the redline... for a reason.

 

I really doubt it has anything to do with the dv. I have a 710N and the same thing happens to me. However, if you haven't upgraded dv's since being chipped, you should do so.

 

Its funny, I typed everything in my above post but nobody read it. I already have the 710N, its less than 2 months old. I tested it and it works fine.

Anyone else? Additionally, I don't really have to go to redline but over 5K. This prevents me from using third gear to its full potential on the highway.

 

yeah, but you didnt say you already upgraded it.

 

redlining in higher gears would do this your tubo is the size of a hair dryer and can only put out so much it falls off around 5500 and this is bringing your boost down if you want to redline get your self a bigger turbo that will go to redline but won't spool till 3500 then you will be happy

 

How come no one is reading my post hahaha?

Quattro sedan, the first few lines in my original post say 710N installed.

Clconversion, I know the ko3 runs out of steam at redline, but that is not what i am talking about. The car looses the ability make more than lets say 5 psi of boost after going past 5k in 3rd. Do you understand what I am saying? So even if I come to a complete stop and go back in 1st, 2nd or 3rd it looses the ability to make boost as though it is in limp mode.

If I turn the car on and off, the problem is solved. However, this is not a solution as turning on and off my car at 65 MPH is not the smartest thing in the world to do.


Any other ideas?