Turbo P0299 Engine Code issue
 

Hi -

I have a 2012 Audi Q5 with approx 75,000 miles on it. Two weeks ago I had my 75K service at the dealer. A week later my check engine light went on. I took it to the dealer thinking it was linked to the recent service. Turns out the car registered a P0299 code and that I would need a new turbo charger at the lovely price of $3600 installed. My jaw dropped. After paying the $200 diagnostic fee, I asked them if they checked the diverter valve, senors or waste gate. The service rep stared at me blankly. I told him that the diverter valve could be bad as can a sensor. I then asked to speak with a tech and they wouldn't let me and just said it was the waste gate. I turned and walked out.

Later in the day I went back to the dealer after doing some research and instead of talking to the service rep, I went to the garage and spoke with a tech. I asked him what the protocol is when they see a P0299 code. He told me that it is almost always the waste gate and they recommend a new turbo. I then asked about the diverter valve, sensors, etc. He told me that could be the problem but their course of action is to replace the turbo. I then asked what he would do if it were his car...you guessed it...he would start by inspecting the diverter valve, then sensor, etc. Pretty crazy that for $200 I paid to have a code read and nothing else.

I then went to a local shop to get a second opinion. They read the codes and got the P0299 code. At least that cost only $80. Like Audi, they really didn't have much to say. What they did do that Audi didn't was clear the codes and turned off the check engine light.

I have since been driving the car for the past two weeks with no noticeable performance issues and the car actually drives great. I have also driven over 300 highway miles with no issues, no decrease in performance and no check engine light. I did not gun the engine but casually accelerated and kept the RPMs between 2,000 - 3,200 RPM (not sure if this is doing anything good or bad, I just don't think I am putting the car under turbo). Car runs great.

My question is whether anyone else has has an experience similar to mine? Could it have been a fluke error code? Shouldn't the code have fired again already? Any additional thoughts?

Also - as an FYI - the stupid dealer that charged me $200 told me the code was static, not intermittent. I will never go to them again.

My relative’s 2011, 2.0T, Q5 had that issue. Threw the P0299 code, cleared the code, came back a few days later. Cleared the code a few more times, came back later.

We both agreed to change the diverter valve first. Didn’t fix the issue. We then changed the sensor, it fixed the problem, and never had the code return in over a year.

Interesting read.

I purchased a used turbo with latest PN, comes with DV and sensor, can look at the sensor PN, I think you are referring to the N75 valve, if you wish when I get home in case it is prefacelift . Also purchased the clip that is recommended to add at the waste gate hinge. That way I will save xxxx when my turbo fails.
My house is becoming a Q5 spare part warehouse :)
Good luck.

Same situation as you however I did replace the diverter valve as there was a tear, then the solenoid that controls the waste gate. Light went off but then returned, car ran great however. Interestingly enough this was in the summer and the check engine was on all summer, once we went into cooler air the light went out and stayed out. As the warmer weather was approaching this past spring I sold the car as I did not want to spend any more on this problem and not pass a E-Check test which I have in my area. I did wonder if the actual boost sensor should have been replaced....? I have speculated if possibly the air density when cold was just enough to turn the light off. The shop that did the work felt the waste gate was fine and did the smoke pressure test also to ensure there were no leaks in the system. They are Audi specialists - the dealer only wanted to replace the turbo like you have experienced which if I could have the money back for my frugality in the cheaper attempts to fix the entire turbo was the best option.

Overall after much research, forum surfing and talking to mechanics I think the waste gate was starting to leak and if you like the car and plan on keeping it the entire turbo is probably the way to go.. I wonder if in the newer models they have made this waste gate reparable as its such a shame you have to replace the entire turbo for a loose little piece of steel.

I'm in the same boat. I've got a 2011 Q5 2.0T with 97,536 miles and have been getting the P0299 CEL code for about 4 months. I've got a OBD2 reader and app that I can clear the code with but it comes back. After search the forums I replaced the diverter valve as a cheap fix to see if the code would return. The car ran great, I had my boost back and it felt great..until a few days later when the CEL came back on. I wasn't a candidate for the oil consumption during the class action during the time frame because it wasn't burning oil at all until about 90,000 so now I have a massive problem.. a turbo that needs replaced and an engine that burns a quart of oil every 3 weeks.

So the clip I mentioned was probably not taken into consideration. The cause of wastegate leak was fixed with the following clip but rather to prevent before it goes bad. If you buy a new turbo or a wastegate with a repair kit (if there is one) add this clip to the wastegate hinge. Not told by your service provider I suppose. There is also a respective service bulletin (TPI). I would first change diverter valve then N75 valve and turbo hoses. Also install the clip.
2. Check your wastegate flap if it is loose, i.e. air leaking out of the system.
You are welcome.

https://cimg8.ibsrv.net/gimg/www.aud...8d8c87e498.jpg

I'm currently dealing with a P0299 code. Came up when the hot temps arrived (102+ most days, with some 110+ already).

I replaced the DV last fall with the BFG DV+, with the variable open spring. It's slightly possible maybe that the valve is sticking since I used a non-motor oil to lube it. I suppose that could be the issue; I plan to remove the DV and inspect and re-lube.

I replaced the N75 and MAP sensors to no avail.

On hot days with the fans running, a start from 0mph can produce a surge in RPM without attendant boost pressure, and the light comes on. Even when I don't get that specific symptom, I get small surges (say, on an on-ramp) and look down to see the light has come on again.

This past week I went on a 2500 mile road trip, and on the way back (an 18hr haul) I noticed that I was not maintaining cruise speed (85mph) on hills and that the turbo wasn't spooling to power (I was showing stagnant positive boost on the monitor) and it would have to shift once it hit -5mph to spool boost and regain the set speed; that's concerning.

I also noticed a long time ago that there was wastegate chatter; that has not worsened with these issues, that I can tell. Sooooo, my plan at this point is to pull the DV and inspect and make sure it functions properly. Since there is very little reason that it would be the issue, it's looking like I have a bad wastegate and will be replacing the turbo sooner than later.

One other thing I began to notice in January and have noticed deteriorate since, is rapid, arrhythmic surges on cruise control; it was after I opened the airbox and placed a low-resistance AFE filter and the new DV; to control I closed the airbox but kept the filter and DV. It's improved in intensity but not frequency. They were particularly bad this past trip, to the point I was getting angry. I wonder if it's the wastegate moving enough back and forth that it's causing boost regulatory issues.

FWIW, most of these issues are simple to do yourself for farrrrr less money and a few tools. I have saved probably on the order of several thousand dollars this year alone by sourcing parts and labor myself.

That sounds like what mine has done. I too replaced the DV but it didn't do much. It ran great for a couple hundred miles then tahdahh the light came back.

Is the 2.0 turbo on the Q5 different than on the A4 which had a 7 yr, 70,000 mile warranty extension from Audi for the wastegate problem? The A4 forums are filled w/the P0299 wastegate problem, yet in this Q5 forum there are hardly any threads on this.

Just like the OP, I also have a 2012 Q5 2.0T with 75k miles on it. I had the P0299 code a year ago. I reset it and went a whole year before the light came back on last week with the same code. I brought it to an indy Audi mechanic who cleared the light and ran diagnostics. He said it looked fine and took my car to get a new inspection sticker in case the light came back on after giving it back to me (it would fail in MA, forcing me to replace the turbo within 21 days). Assuming the light will come back again soon, what are my next steps? Replace the N75 sensor?

Steps
1. Check wastegate play and also the flap if it closes fully and does not move up and down.
2. If both are ok then change the N75, MAP, and or DV valve:
a) N75 WasteGate Frequency Control N75 Valve 06F906283F or 7.00470.07.0
b) Diverted valve: 06H145710C
3. If you dont have the clip install the clip. See above.
4. If there is play you need to service/repair/or change the turbo charger.
6. Turbo charger catridge may also fail??? Checks fins also.
7. You will also need a new mounting gasket kit if turbo charger is removed.

Maybe someone else has better suggestion. My Q5 2009 turbocharger still works fine, but have got a clip and will install on first occasion. Also when I upgraded my intercooler to a larger one from Audi Q5 diesel, I changed the 2 intercooler in out pipes (A4 A5 pipe part numbers should also work and confirmed compatible by me).