Excessive smoke from the exhaust - A7 3.0TDI 2011

[AudiNike12]

Hi there

I hope someone can give me some pointers here. When the car reaches operating temperature, lots of smoke appears from the exhaust. When I'm coming to a stop, it's like it's a fire back there but calms down a bit shortly. It seems it's only happening when reaching operating temperature. Nothing before that. I've read that on earlier 3.0TDI's, faulty injectors are a common cause of this. I've checked some values in VCDS but I don't really know what I'm looking at. Seemed to be in spec. The smoke seems to be whiteish

I don't really wanna drive the car until this is fixed so any help would be appreciated

[benlaud87]

I’m pretty sure that faulty injectors are most always the cause of white smoke coming from diesel vehicle exhaust pipes.

I know you can have your injectors tested, but I don’t know the cost associated with that.

[AudiNike12]

Recently doing a Stage 1 isn't gonna be the cause of the smoke right? It's from a proper firm. Don't remember if it was like this before or not

I'm thinking of testing the injectors at a Bosch Diesel place in town. Do you know if they remove them from the car and test them?

[benlaud87]

Was this a custom tune or was it just an off the shelf tune? If you have VCDS, I would run a log file for your tuner and send it to them to see if they can see what’s wrong.

Diesel injector testing I have seen would require them to be removed so that output can be properly observed.

[benlaud87]

Forgot to add: if you have the ability to revert your tune back to stock, this would tell you whether or not the tune is the issue.

Your tuner can adjust fuel output of the injectors so long as they aren’t faulty.

[AudiNike12]

I do have a tool I can connect to the car to revert back to stock easily. I will try that first

[TexasDfwS4]

After removing the tune drive it a bit to clear the system out.

[AudiNike12]

Now the DPF warning light came on when I started the car. Went for a run and it smoked like usual(burning smell). Scanned the car and got fault code:

10274 - EGR Temperature Sensor 1
P040B 00 [039] - Implausible Signal
MIL ON - Confirmed - Tested Since Memory Clear

Have not reverted back to stock yet. Anyone know which sensor this is and where it is located? I've tried googling around but it seems there are several sensors

It also says in the "Readiness" column in VCDS: EGR regeneration failed or incomplete. I guess that's why the DPF light is on?

Also checked the temperature of the EGT sensors. With the engine off: Sensor 1,3 and 4 looked like normal ambient temperatures while Sensor 2(have read that this is not actually a EGT sensor on some engines. Mine is CDUC) is stuck at 222 degress at all times.

Can a failed EGR temp sensor lead to a failed or incomplete DPF regeneration?

[AudiNike12]

And now the car is in limp mode with glowplug light flashing. From what I can gather: It's in limp mode because the calculated soot value is above 40g(41g) and the reason for this is because it can't regenerate and burn off soot. And the reason why it can't regenerate by itself is maybe because of a bad temp sensor. Am I on the right track or completely off? My measured soot value is 0g though. Is that because I've done a DPF reset when I installed the tune? No smoke in limp mode though

[benlaud87]

What is the code thrown in VCDS?

[AudiNike12]

First it was:

10274 - EGR Temperature Sensor 1
P040B 00 [039] - Implausible Signal

Then it added this when it went in limp mode(happened the first startup after the tune up also):

5188 - Diesel Particle Filter
P2463 00 [175] - Excessive Soot Accumulation

5189 - Particulate Trap Bank 1
P2002 00 [047] - Efficiency Below Threshold

I have now replaced the temp sensor. Did a DPF reset and deleted the codes. And it is back to normal. But for how long? I'll take it to work tomorrow and see what happens

[benlaud87]

Time to delete that dpf/egr?

Do you get up to highway speeds where the dpf would be able to “self clean”?

[AudiNike12]

I've 45km to work. I can get up to a decent speed but don't know if that's enough time. How do I know when it regenerates by itself?

[AudiNike12]

Drove the car to work and back. No smoke at all. Fingers crossed that the EGT sensor was the issue

[benlaud87]

I hope it all works out

[AudiNike12]

Aaaaand....it still smokes Guess I'll try and revert back to stock. What is it that makes it smoke though? Burning fuel? Soot?

[benlaud87]

Excess fuel

[AudiNike12]

Yeah... I went back to stock...Didn't help.. DPF light came on pretty fast and it started smoking..I don't know what to do next to be honest. It's up to 38g calculated soot so it's gonna be in limp mode after my next drive again. Over 40g

Could it still be anything to do with my injectors? Doesn't seem likely though

[Burnt]

Stage 2 with DPF/EGR delete here we come. In reality, prob need to take it to a shop. Sounds like something isn't burning right. Black smoke or white smoke? White smoke unburnt fuel possibly. Keep it stock and let someone diagnose it, if they can't, run it more then take it to the stealership under dieselgate warranty.

[AudiNike12]

It is white smoke. Guess I'll find someone who can take a look at it. Unburnt fuel, what does that mean? Does it get too much?

The weird thing is. When looking in VCDS, my measured soot value is 0 and my measured ash value is 0. They never change. Always 0. It's only the calculated soot that is changing. Is this normal?

[AudiNike12]

Are these normal values for the injectors?

IDE00365 Injection quantity deviation cylinder 1 0.61 mg/stroke
IDE00366 Injection quantity deviation cylinder 2 0.42 mg/stroke
IDE00367 Injection quantity deviation cylinder 3 -0.14 mg/stroke
IDE00368 Injection quantity deviation cylinder 4 -0.02 mg/stroke
IDE00369 Injection quantity deviation cylinder 5 -0.89 mg/stroke
IDE00370 Injection quantity deviation cylinder 6 0.02 mg/stroke

Seems like No.5 is compensating for No.1? Don't know much about this. No.1 was actually around 0.8

[AudiNike12]

So turns out the white smoke is oil smoke. It's leaning towards a bad turbo when talking to people. But can the turbo leak oil through the pressure side while still working just fine? Don't notice any excessive play. It does stop smoking when going into limp mode. Does the turbo not work fully then?

[AudiNike12]

Well, not being any closer to a solution. So the DPF is coming out, sending it to a firm for cleaning. The injectors are coming out, sending them to a Diesel Bosch firm for testing. The turbo is coming out for inspection and possible replacement

[AudiNike12]

So just closing this one up. Took out the DPF and a previous owner had cut it open and removed a lot of the DPF material(it was a hole straight through) and welded it together again. Probobaly coded out the sensors also. So when I uploaded the tune file it ruined what they did and it started smoking and all sorts. I replaced the DPF and so far so good. I managed to test the injectors before and they're all good. So hopefully I can put this behind me now *crosses fingers*

[benlaud87]

Wow, never would have guessed that. How much did a replacement DPF run you?

[Gunmeister]

Wow nightmare!

[AudiNike12]

Yeah fun times. It cost me a whopping $3000 I'll have to drive this car until I'm six feet under lol

[Avantly]

Interesting thread. One thing you should do regularly if you are unable to delete the environmentally-unfriendly tier IV passenger car emissions is to make sure your adblue injector is not clogged up at the nozzle. I have seen the SCR's on 3.0TDI completely clogged with crystallized DEF and soot/carbon. SCR starts to clog up and it seems that DPF follows right after. The adblue injectors are easy to check visually, it's only a single screw to pop it off the pipe fitting, and easy to clean.

[AudiNike12]

I don't have adblue on this car

[AudiNike12]

I want to drive this car off a cliff right now. The problem is back . DPF light is on and it's smoking. Soon limp mode will follow. It hasn't regenerated once in 600 miles. The calculated soot keeps rising. The accumulated soot is at 0.59g. Oil ash is 0. I'm down $3000 and out of ideas

[Gunmeister]

I don't know how to help but I hope someone can help you soon. I have a 2016 TDI, and I've never had these problems, but I think if the previous owner didn't change things, maybe you wouldn't be getting so screwed over right now.

[AudiNike12]

Yeah, who knows. But the oil smoke has to come from somewhere right?

[Gunmeister]

Did you ever solve your issue?

[AudiNike12]

I replaced the EGT sensor pre-dpf. It was stuck on 222 degrees. It then showed the correct temperature and the engine light disappeared. I also found a break in the wire to the DPF pressure sensor. Fixed that and the glow thread light on the dash disappeared. Both of these things would make the car not regenerate. So it all seems ok now :)

[Gunmeister]

Nice work!

[AudiNike12]

Bringing this back because that was not the problem. Someone must have done something with the ECU. Because the temperature it shoud've gotten from EGT sensor 4, it got from the EGR temp sensor. And vice versa. Since the temperature is much lower at the EGR, the temperature it showed when regenerating was not hot enough, so it could not finish the regeneration. What I ended up doing was making 2 adapter cables so I could switch the connectors to those 2 sensors and VOILA! Now the temperatures are correct and haven't had a problem since. This was a couple of months ago. I discovered this while I was unplugging one sensor after another while monitoring with VCDS. Mental lol

My theory is that when they messed with the DPF(cut it open, removed material), they didn't want the car to regenerate. So they changed something within the ECU and this was the solution, I don't know

[NorthernGTI]

Bringing this back because that was not the problem. Someone must have done something with the ECU. Because the temperature it shoud've gotten from EGT sensor 4, it got from the EGR temp sensor. And vice versa. Since the temperature is much lower at the EGR, the temperature it showed when regenerating was not hot enough, so it could not finish the regeneration. What I ended up doing was making 2 adapter cables so I could switch the connectors to those 2 sensors and VOILA! Now the temperatures are correct and haven't had a problem since. This was a couple of months ago. I discovered this while I was unplugging one sensor after another while monitoring with VCDS. Mental lol

My theory is that when they messed with the DPF(cut it open, removed material), they didn't want the car to regenerate. So they changed something within the ECU and this was the solution, I don't know

What a roller coaster of a thread. Why not just do a full delete with tune?

[Avantly]

It sounds to me like he already has a partial delete and it wasn't done right. If the DPF has been hollowed out I'd do the same to the SCR (if equipped) and turn it all off... Tune not necessary though I know people love to do that to these engines. The deleted 3.0TDI's I've driven felt like they had a mild tune just from the elimination of this emissions nonsense xD

[AudiNike12]

What a roller coaster of a thread. Why not just do a full delete with tune?

Yup, me head hurts. But it's finally sorted after a year and a half

Since I've splashed out $3000 on a new DPF, it seems pointless to do a delete now Should have done it before, then my wallet would be a bit thicker lol

[AudiNike12]

It sounds to me like he already has a partial delete and it wasn't done right. If the DPF has been hollowed out I'd do the same to the SCR (if equipped) and turn it all off... Tune not necessary though I know people love to do that to these engines. The deleted 3.0TDI's I've driven felt like they had a mild tune just from the elimination of this emissions nonsense xD

What is SCR?