Hey all, first post, please bear w me.

2007 A4 2.0T quattro

Just purchased the car. The dealer had just replaced the turbo. The car ran great for the first week then started throwing misfire codes. Thought it was the coils, dealer replaced them and it still happened. They were Napa crap so I decided to get Audi coils and plugs. Voila, one of the new plugs from the dealer had failed. The porcelain part on the plug came loose and made the plug burn the end off.

So all better, no misfires. Now I'm getting over boost. Keep getting thrown into limp mode. My first thought is the diverter which came new on the turbo. How would I adjust it? Screw it in or out? Should I look elsewhere for the problem?

 

read the stickies above for more info about the audi turbo design. im not sure there is any way to adjust the diverter valve. it not like a typical blow off valve or wastegate. i recommend getting a code reader or diagnostic tool. i recently picked up a bluetooth obd2 transmitter and bought the Torque diagnostic app (app store and play store ~$5) and it is packed full of useful tools and info. try something like this to check MIL codes and look at boost levels, intake temps, a/f ratios, and tons more.

 

I'm assuming that it wasn't an audi dealer? Stock diverters won't adjust. I'm curious what parts went in since they used nappa parts. A4s don't like aftermarket parts or chips for that matter. Get yourself a vagcom full version. If you're used Audi driver your insane to go without it. They aren't cheap, but they'll pay for themselves so to speak, $450 plus shipping. Code readers can't read every fault code these cars put out and in your case that's important.

I'm concerned about that turbo hope it's an actual k03 they put on. But first I should ask how'd you come up with the diagnosis of overboost?

 

One of the first things I realized I needed was a reader. I got the OBD Link LX Bluetooth reader. I'm getting an overboost code regularly. The torque app showed a boost of 28 psi. This is either really bad or something is off.

I'll try to figure out where they bought it from today.

 

https://www.dropbox.com/s/v6luefeljsquisp/2014-09-07%2021.15.22.png?dl=0

Red arrow is where it maxed out.


Is it possible to adjust the waste gate? Could that be the cause?

 

The diverter valve really wont cause the vehicle to over boost. Chances are it has more to do with the N75 valve or the waste gate. Whoever installed the turbo may not have pre tensioned the wastegate arm or tensioned it too much.

To much or too little tension on the arm can cause the boost to come on differently. If the ECU gets a reading that's too aggressive or lower than expected it can throw a code.

Usually it will be positive or negative deviation - post the ECU codes up if you can get them. You'll likely need to have the ECU scanned by a dealer or someone with VAG-COM as typically this type of code wont be read by an OBDII scanner.

Jason

 

I'm bringing it to the dealer. I bought a warranty that covers everything so I'll let them go through it and solve it. It'll be worth it. $100 deductible....