[dlysnes]

Hi
The EGR warning is gone now, however I do have a leak somewhere. Sounds like a 2nd turbo. Need to FInd out where it is before I'll resume troubleshooting.
However, I did not see any faults on MAF, and EGR valve was replaced. Might be all my combined efforts with steaming etc actually cleared it, but I'm worried that the EGR cooler is clogged..

 

[dragline1570]

A

Thanx again. Yep, the MAF reports lower flow when EGR is open, but I guess it's not low enough for the ECU to be happy. As I have already cleaned out EGR pipe, replaced EGR valve and checked many of the other, big tubes I suspect EGR cooler to be the reason for this. These issues are quite common up here in the north. Replacing EGR cooler is a massive job.
I could also try cleaning the intake manifold as it seems to be an easier job, actually. I'll keep this thread updated as I dig more.

So far as i can see you didn't replace the EGR exhaust gas temperature sensor.
Why would this not be near the top of the list in your fault finding.
I know you get that fault about EGR insufficient flow when you put a restrictor in the EGR system.
The sensor isn't seeing the temp rise it thinks it should so it faults on low flow.
Its not rocket science.

Regards
Drag

 

[dlysnes]

A


So far as i can see you didn't replace the EGR exhaust gas temperature sensor.
Why would this not be near the top of the list in your fault finding.
I know you get that fault about EGR insufficient flow when you put a restrictor in the EGR system.
The sensor isn't seeing the temp rise it thinks it should so it faults on low flow.
Its not rocket science.

Regards
Drag

Thanx! I'll order a new temp sensor too

 

[dlysnes]

Thanx! I'll order a new temp sensor too

I see for my car I need the 059906088P sensor. Expensive sensor indeed..

 

[adidas]

I have the same motor, CASA, and had the same problem. Took the EGR out and cleaned it but nothing happened. After that i thought to change the gas station, highest quality diesel and the results started to come. Now it was just once a week, check engine on and after a few rides check engine off. Next i bought a MAF cleaner and cleaned it a few times (dont touch it, just spray it) and let it dry for one hour or so. After that everything was fine, no more check engine on and no more errors in VCDS. Its been half year since. Fingers crossed.
The usual suspects are: MAP and MAF sensors. If you decide to change them remember they need a basic setting with VCDS. Not sure if both or just one of them.

 

[dlysnes]

I have the same motor, CASA, and had the same problem. Took the EGR out and cleaned it but nothing happened. After that i thought to change the gas station, highest quality diesel and the results started to come. Now it was just once a week, check engine on and after a few rides check engine off. Next i bought a MAF cleaner and cleaned it a few times (dont touch it, just spray it) and let it dry for one hour or so. After that everything was fine, no more check engine on and no more errors in VCDS. Its been half year since. Fingers crossed.
The usual suspects are: MAP and MAF sensors. If you decide to change them remember they need a basic setting with VCDS. Not sure if both or just one of them.

Hi adidas
What kind of cleaner did you use?

 

[dlysnes]

I just had a 2nd look at my pictures.. It seems to be a gap in the box the MAP sensor is in. Could this actually be the root cause??

 

[adidas]

Differential pressure sensor can be also the culprit

2011 Volkswagen Touareg TDI Sport Utility 3.0L TDI V6 DIESEL A/T Diesel Exhaust Fluid (DEF) Pressure Sensor. Exhaust Gas Differential - 059906051A - Genuine Volkswagen Part

Diesel Exhaust Fluid (DEF) Pressure Sensor. Exhaust Gas Differential Pressure Sensor. MAP SENSOR. 2011 Volkswagen Touareg TDI Sport Utility 3.0L TDI V6 DIESEL A/T. Genuine Volkswagen Part - 059906051A (059-906-051-A)

parts.vw.com

I used this cleaner, but any airflow cleaner should work:

 

[adidas]

Error is back, but not MIL on dash. I think is triggered by going above certain RPM.
@dlysnes if you find a cure, leave a reply here. Thanks

 

[dragline1570]

I see for my car I need the 059906088P sensor. Expensive sensor indeed..

Yep i thinks so as even though its a CASA eng the 2010 end is a bit different to the 2011 and the 059906088P fits the 2011.

regards
Drag

 

[dragline1570]

Error is back, but not MIL on dash. I think is triggered by going above certain RPM.
@dlysnes if you find a cure, leave a reply here. Thanks

Its the EGR temp sensor i say

regards
Drag

 

[adidas]

@dragline1570 And it can be tested via VCDS?

 

[Edds]

Guys, how is it going? Any further updates? I have changed both MAF sensors and EGR valves on my v8, but still receive both errors. It usuall takes 4-5 days for the errors to pup up, after I clean them.

 

[david.lysnes]

No news, but also no warning anymore. I have not replaced any parts, yet. I wonder if the steaming I did actually did the trick, but that's in no way confirmed. Will do it again this summer.

Sent fra min CLT-L29 via Tapatalk

 

[dlysnes]

A


So far as i can see you didn't replace the EGR exhaust gas temperature sensor.
Why would this not be near the top of the list in your fault finding.
I know you get that fault about EGR insufficient flow when you put a restrictor in the EGR system.
The sensor isn't seeing the temp rise it thinks it should so it faults on low flow.
Its not rocket science.

Regards
Drag

Hi dragline1570. Actually, today I got a new error code. P0401 is gone, but I now got P040D Exhaust Gas Recirculation Temperature Sensor A Circuit High .
So, this indicates maybe a faulty sensor so I'll go ahead and order it. It's difficult to get the right one, though. Anyone knows which is the correcty sensor (part number) for CAS engine, 7p5 V6 3.0L TDI?

 

[david.lysnes]

Just a short update. After replacing egr temp sensor the P0401D is gone. I also did a dpf regeneration run (>2500 rpm, over 60km/h for 20 mins), and no traces of p0401, not even pending.
Hopefully won't see it again.

Sent fra min CLT-L29 via Tapatalk

 

[dragline1570]

Just a short update. After replacing egr temp sensor the P0401D is gone. I also did a dpf regeneration run (>2500 rpm, over 60km/h for 20 mins), and no traces of p0401, not even pending.
Hopefully won't see it again.

Sent fra min CLT-L29 via Tapatalk

Good result
Regards
Drag

 

[adidas]

@david.lysnes Awsome! Part number and where is located?

 

[david.lysnes]

@david.lysnes Awsome! Part number and where is located?

See my other post: Error code P040D on 2011 V6 3.0 TDI

However, this did not fix p0401 error, only p040d/b. But you might get lucky, of course
The sensor is to the right of egr valve, orange socket. Make sure to either get a lambda socket (17mm), or make your own as I did

Sent fra min CLT-L29 via Tapatalk

 

[dlysnes]

Hey guys
Short update. It turned out that the howling noise was coming from a leaking flange gasket in the EGR return pipe to exhaust manifold. Sorted that one out (some mechanic had previously used wrong bolts and ripped the threads..) P0401 still turned up after securing the flange, and the howling noise was still there. Workshop is 90% sure it's the turbocharger leaking gases, so bought a refurbished one and I'm currently in the process of removing / reinstalling. As a side note, this engine does not have the bracket below the turbo with the oil return in it, but has the center mounted joined return pipe with o-ring ( see exhaust gas turbocharger AUDI A5/S5 COUPE/SPORTBACK part number 3)

I'll give an update after new turbo is fitted and I've had a few test runs. Hopefully both P0401 will be gone. The turbo has been giving other noises too, so I gess it's time for replacing anyway.