07 B7 A4 2.0T Only boosting 1 or 2 PSI, already replaced DV, new turbo 45k ago.

[TWiST]

2007 B7 A4 with 144k Miles, replaced the DV with a 710D (which I already had) just to check it and same issue persists, throwing code P0299 and getting only 1 or 2 PSI boost.

Turbo and manifold was replaced like 45k miles ago under extended warranty as it had a crack in the housing. I have recently replaced the cam follower, which did not have much wear and that valve on the back of the motor where the cam chain is (cant remember the name of it, for unrelated issue of the car shutting off, which it fixed).

I really hope its not the turbo. When I was changing the DV today, I did notice some oil on the wiring connector which I do not believe was there before when I changed it like 6 months ago. I have been noticing some oil around my oil cap which was a sign of the PCV before going bad, but I dont recall losing all my power back when that happened, when I first had the car.

Any ideas, gentlemen?

Thanks!

[Rastboostin]

It could be the PCV, though I'm not sure about it causing a P0299. Could be the wastegate on your turbo may be faulty? I've seen a few people report that, even on turbos that had like 39k miles. Did you check to make sure the DV was securely fastened all the way? Just throwing out some ideas

[Jake@JHM]

Check all of your intercooler hoses and PCV.

If those are bust, look at your waste gate/

[TWiST]

Unless i missed a hose i have checked them all pretty good, granted i knew much more about the b5 s4 system then i do about this a4. I also was doing some troubleshooting on the N75 and snapped a plastic nipple off, so i replaced that. When i was testing stuff i noticed i was getting no boost with the power disconnected from the N75 and when i put the new one on its the same 1 or 2 psi.

I checked the DV and replaced the 710D with another 710D i had and same thing 1 or 2 PSI.

Later this evening i am going to try to pull the cat and downpipe back and see if i can feel the turbine for play.

I have been seeing a little oil around my cap that is fresh, so im guessing my PCV is on its way out, but from everything ive read it wouldn't cause this drastic loss of boost, anyless you guys have hands on experience with that happening and then its like, should i buy another stock one or a fix or catchcan. Im a firm believer in upgrading parts when they fail when i can, instead of just replacing them.

As much as i would love to make this an excuse to upgrade the turbo to K04 or FT, i wasn't really mentally or financially prepared for this.

To test the wastgate i will need to build one of those testers ive seen, and can you replace just that. I don't think you can, but that would be nice haha. My car has had a Neuspeed tune on it since 2007 when i got it got a fantastic deal as I live near there Camarillo headquarters and its a tad less aggressive which I was looking for at the time.

Sent from my LG-LS980 using Tapatalk

[TWiST]

After checking some things out before I was going to try to pull the cat and check the turbo for shaft play, I noticed that I can move the rod as if manually actuating the wastegate by hand. From everything I have read, I don't think your suppose to be able to do that? Before I bother sliding the cat back to feel the turbine on the turbo, can anyone confirm that I should NOT be able to move that rod?

**UPDATE**
I was just looking at a pic of the turbo, I guess its suppose to move like a gas pedal so at least I know its not stuck I guess.

[TWiST]

I moved the cat back today to inspect the turbine, shaft and wastegate flap thing. I manually moved the actuator rod and it opened and closed just fine, I could not move the turbine shaft in any direction and it spun freely when lightly spinning it, so I do not think it had ANY shaft play in any direction. I did notice if I put just a little pressure from the side while trying to spin it, it would not let me. Not sure if that is normal or not.

Here is a pic.


https://dl.dropboxusercontent.com/u/7001168/b7%20a4%20turbine%20k03.jpg


Everything seems to look ok. Next I decided to take a look at the CAT, since it was already opened up.


https://dl.dropboxusercontent.com/u/7001168/b7%20a4%20cat.jpg


Not so good :( WOW, it is TOTALLY melted, took the chunks that broke off and melted them closing off the honeycomb, there were some chunking lying in there before I took this pic. I am in the process of gutting my cat and making my own sort of test pipe since it is fried anyways to do some testing with for now.

I would like to add I have a TIP and removing the cat was totally different then what I had seen in other writeups. Main difference being, I had to unbolt the downpipe from the cat while it was still on the car, and remove the cat from the top of the engine bay. It was not extremely difficult, but having a second person to hold the back bolt of the downpipe to cat connection would be helpful (12mm), while another person is underneath the car working on the bolts facing towards the back of the car (13mm).

So my question that will hopefully be answered tomorrow after I finishing gutting my cat, and putting it back on the car, is.. Was my cat breaking down what lost me all my boost and power, or did my turbo failing cause my broken down cat to melt due the engine trying to make up for the lack of boost and what is failed on the turbo, seems like the wastegate canister is the only thing left?

Tune in tomorrow, to look at some more stuff you can be glad is not happening to you at the moment lol.

[aluthman]

I'd say all your issues are likely from your toasted kitty.

[twstdbyboost]

Punch the cat and see what happens besides p0420.

[p07503p]

Any luck with this? im sort of having the same problem. my boost was fluctuating pretty bad so i installed a mbc about a week ago and that fixed the fluctuation. while driving on the highway today, all of a sudden my boost dropped to 0 and wouldnt go more than 1 or 2 psi. all the lines are fine that i added for the mbc so im stuck.

[Jake@JHM]

Time for this: http://jhmotorsports.com/shop/catalog/exhaust-test-pipe-jhm-catless-test-pipe-for-b7-a4-20t-p-1852.html

[p07503p]

Time for this: http://jhmotorsports.com/shop/catalog/exhaust-test-pipe-jhm-catless-test-pipe-for-b7-a4-20t-p-1852.html

i already have a 2.5in test pipe. btw i have a b6 1.8 not b7. any other ideas?

[Jake@JHM]

i already have a 2.5in test pipe. btw i have a b6 1.8 not b7. any other ideas?

Fail on my part. I saw the toasted cat above and saw it was a 2.0t thread.

For yours issue, sounds like you have a boost leak. Check all your hoses and diverter valve.

[p07503p]

i checked for leaks and the dv is fine. im thinking it could be something with the wastegatge.

[Jake@JHM]

i checked for leaks and the dv is fine. im thinking it could be something with the wastegatge.

The wastegate could be stuck open, or your n75 has failed.